Revellers watch as fireworks explode in front of Vienna's city hall as Austria's capital ushers in the New Year, January 1, 2016. REUTERS/Leonhard Foeger 

Revellers watch as fireworks explode in front of Vienna's city hall as Austria's capital ushers in the New Year, January 1, 2016. REUTERS/Leonhard Foeger 

German police secure the main train station in Munich January 1, 2016. German police evacuated two train stations in Munich late on Thursday, saying on Twitter they had received a tip regarding a planned militant attack on New Year's Eve in the Bavarian capital. REUTERS/Michael Dalder

Fireworks explode during New Year celebrations in Sarajevo, Bosnia and Herzegovina, January 1, 2016. REUTERS/Dado Ruvic 

Fireworks explode during New Year celebrations in Sarajevo, Bosnia and Herzegovina, January 1, 2016. REUTERS/Dado Ruvic 

German police secure the main train station in Munich January 1, 2016. German police evacuated two train stations in Munich late on Thursday, saying on Twitter they had received a tip regarding a planned militant attack on New Year's Eve in the Bavarian capital. REUTERS/Michael Dalder

Fireworks explode during New Year celebrations in Sarajevo, Bosnia and Herzegovina, January 1, 2016. REUTERS/Dado Ruvic 

German police secure the main train station in Munich January 1, 2016. German police evacuated two train stations in Munich late on Thursday, saying on Twitter they had received a tip regarding a planned militant attack on New Year's Eve in the Bavarian capital. REUTERS/Michael Dalder

Fireworks explode during New Year's celebrations in Sarajevo, Bosnia and Herzegovina, January 1, 2016. REUTERS/Dado Ruvic 

Fireworks explode during New Year celebrations in Sarajevo, Bosnia and Herzegovina, January 1, 2016. REUTERS/Dado Ruvic 

German police secure area near the main train station in Munich January 1, 2016. German police evacuated two train stations in Munich late on Thursday, saying on Twitter they had received a tip regarding a planned militant attack on New Year's Eve in the Bavarian capital. REUTERS/Michael Dalder

German police secure the main train station in Munich January 1, 2016. German police evacuated two train stations in Munich late on Thursday, saying on Twitter they had received a tip regarding a planned militant attack on New Year's Eve in the Bavarian capital. REUTERS/Michael Dalder

German police secure the main train station in Munich January 1, 2016. German police evacuated two train stations in Munich late on Thursday, saying on Twitter they had received a tip regarding a planned militant attack on New Year's Eve in the Bavarian capital. REUTERS/Michael Dalder

Fireworks explode in the sky during New Year celebrations in Sofia, Bulgaria on January 1, 2016. REUTERS/Pierre Marsaut 

Fireworks explode in the sky during New Year celebrations in Sofia, Bulgaria on January 1, 2016. REUTERS/Pierre Marsaut 

German police block the road near the main train station in Munich January 1, 2016. German police evacuated two train stations in Munich late on Thursday, saying on Twitter they had received a tip regarding a planned militant attack on New Year's Eve in the Bavarian capital. REUTERS/Michael Dalder

German police secure the main train station in Munich January 1, 2016. German police evacuated two train stations in Munich late on Thursday, saying on Twitter they had received a tip regarding a planned militant attack on New Year's Eve in the Bavarian capital. REUTERS/Michael Dalder TPX IMAGES OF THE DAY

Fireworks explode during New Year's Day celebrations in Brussels, January 1, 2016, after authorities on Wednesday called off the usual New Year's Eve fireworks display in the capital, citing fears of a possible militant attack. REUTERS/Francois Lenoir 

A vehicle of Mexico's National Migration Institute (INM) leaves the immigration office while a cameraman films at Iztapalapa neighborhood in Mexico City, Mexico, December 30, 2015. Ethan Couch, the Texas teenager derided for his "affluenza" defense in a deadly drunken-driving case, won a weeks-long in delay in extradition from Mexico, while his mother was in a Los Angeles jail on Thursday after being deported. Picture taken December 30, 2015. REUTERS/Edgard Garrido 

French Rafale fighter jets parked on the flight deck of France's Charles de Gaulle aircraft carrier are seen in Manama December 31, 2015. REUTERS/Kenzo Tribouillard/Pool 

The tail of the Douglas DC-3 plane owned by rock and roll legend Ricky Nelson is suspended from the ceiling of The Williams House Museum in De Kalb, Texas December 18, 2015. Nelson?s plane crashed in the small East Texas town on December 31, 1985, killing him and six other passengers. For years, pieces of the airplane rested in a barn in east Texas with no one to claim it. REUTERS/Lisa Bose McDermott 

A French Super Etendard fighter jet parked next to French Rafale fighter jets, on the flight deck of France's Charles de Gaulle aircraft carrier, is seen in Manama December 31, 2015. REUTERS/Kenzo Tribouillard/Pool 

French Rafale fighter jets parked on the flight deck of France's Charles de Gaulle aircraft carrier are seen in Manama December 31, 2015. REUTERS/Kenzo Tribouillard/Pool 

Fireworks explode in the sky during New Year celebrations in Sofia, Bulgaria, January 1, 2016. REUTERS/Pierre Marsaut 

Fireworks explode in the sky during New Year celebrations in Sofia, Bulgaria, January 1, 2016. REUTERS/Pierre Marsaut 

A French Rafale fighter jet parked on the flight deck of France's Charles de Gaulle aircraft carrier is seen in Manama December 31, 2015. REUTERS/Kenzo Tribouillard/Pool 

A French Super Etendard fighter jet parked on the flight deck of France's Charles de Gaulle aircraft carrier is seen in Manama December 31, 2015. REUTERS/Kenzo Tribouillard/Pool 

Fireworks explode over the temple of the Parthenon atop Acropolis hill during New Year's day celebrations in Athens, Greece, January 1, 2016. REUTERS/Alkis Konstantinidis

Fireworks explode over the temple of the Parthenon atop Acropolis hill during New Year's day celebrations in Athens, Greece, January 1, 2016. REUTERS/Alkis Konstantinidis

Fireworks explode over the temple of the Parthenon atop Acropolis hill during New Year's day celebrations in Athens, Greece, January 1, 2016. REUTERS/Alkis Konstantinidis

Fireworks explode over the temple of the Parthenon atop Acropolis hill during New Year's day celebrations in Athens, Greece, January 1, 2016. REUTERS/Alkis Konstantinidis

Fireworks explode next to the Quadriga sculpture atop the Brandenburg gate during New Year celebrations in Berlin January 1, 2016. REUTERS/Hannibal Hanschke

Fireworks explode next to the Quadriga sculpture atop the Brandenburg gate during New Year celebrations in Berlin January 1, 2016. REUTERS/Hannibal Hanschke

Fireworks explode next to the Quadriga sculpture atop the Brandenburg gate during New Year celebrations in Berlin January 1, 2016. REUTERS/Hannibal Hanschke

Fireworks light the sky over the Kremlin during New Year's Day celebrations in central Moscow, Russia, January 1, 2016. REUTERS/Tatyana Makeyeva 

Fireworks explode next to the Quadriga sculpture atop the Brandenburg gate during New Year celebrations in Berlin January 1, 2016. REUTERS/Hannibal Hanschke

Fireworks explode over the temple of the Parthenon atop Acropolis hill during New Year's day celebrations in Athens, Greece, January 1, 2016. REUTERS/Alkis Konstantinidis

A French Super Etendard fighter jet parked on the flight deck of France's Charles de Gaulle aircraft carrier is seen in Manama December 31, 2015. REUTERS/Kenzo Tribouillard/Pool 

Simon Ammann from Switzerland soars through the air during the trial round for the second jumping of the 64th four-hills ski jumping tournament in Garmisch-Partenkirchen, southern Germany, December 31, 2015. REUTERS/Michael Dalder

Daniel-Andre Tande from Norway soars through the air during the trial round for the second jumping of the 64th four-hills ski jumping tournament in Garmisch-Partenkirchen, southern Germany, December 31, 2015. REUTERS/Michael Dalder

Johann Andre Forfang from Norway soars through the air during the trial round for the second jumping of the 64th four-hills ski jumping tournament in Garmisch-Partenkirchen, southern Germany, December 31, 2015. REUTERS/Michael Dalder

A vehicle of Mexico's National Migration Institute (INM) leaves from the immigration office at Iztapalapa neighborhood in Mexico City, Mexico, December 30, 2015. Ethan Couch, the Texas teenager derided for his "affluenza" defense in a deadly drunken-driving case, won a weeks-long in delay in extradition from Mexico, while his mother was in a Los Angeles jail on Thursday after being deported. Picture taken December 30, 2015. REUTERS/Edgard Garrido 

Severin Freund from Germany soars through the air during the trial round for the second jumping of the 64th four-hills ski jumping tournament in Garmisch-Partenkirchen, southern Germany, December 31, 2015. REUTERS/Michael Dalder

Peter Prevc from Slovenia soars through the air during the trial round for the second jumping of the 64th four-hills ski jumping tournament in Garmisch-Partenkirchen, southern Germany, December 31, 2015. REUTERS/Michael Dalder TPX IMAGES OF THE DAY

Fireworks explode over the temple of the Parthenon atop Acropolis hill during New Year's day celebrations in Athens, Greece, January 1, 2016. REUTERS/Alkis Konstantinidis TPX IMAGES OF THE DAY

A worker of Mexico's National Migration Institute (INM) keep watch watch on a street outside the immigration office at Iztapalapa neighborhood in Mexico City, Mexico, December 30, 2015. Ethan Couch, the Texas teenager derided for his "affluenza" defense in a deadly drunken-driving case, won a weeks-long in delay in extradition from Mexico, while his mother was in a Los Angeles jail on Thursday after being deported. REUTERS/Edgard Garrido 

Local swimmers pray to the sun during sunrise for calm waters and good fortune in the new year in Odawara, Kanagawa prefecture, west of Tokyo, Japan, January 1, 2016. REUTERS/Yuya Shino 

Revellers celebrate New Year's Day in central Moscow, Russia, January 1, 2016. REUTERS/Tatyana Makeyeva 

Revellers celebrate New Year's Day in central Moscow, Russia, January 1, 2016. REUTERS/Tatyana Makeyeva 

People look at the sun during sunrise in Odawara, Kanagawa prefecture, west of Tokyo, Japan, January 1, 2016. REUTERS/Yuya Shino 

Local swimmers walk out from the ocean after praying to the sun during sunrise to wish for calm waters and good fortune in the new year in Odawara, Kanagawa prefecture, west of Tokyo, Japan, January 1, 2016. REUTERS/Yuya Shino 

French Defence Minister Jean-Yves Le Drian (R) celebrates New Year's eve with French soldiers in France's Charles de Gaulle aircraft carrier in Manama December 31, 2015. REUTERS/Kenzo Tribouillard/Pool

French Defence Minister Jean-Yves Le Drian (C) poses for pictures as he celebrates New Year's eve with French soldiers on France's Charles de Gaulle aircraft carrier in Manama December 31, 2015. REUTERS/Kenzo Tribouillard/Pool 

Local swimmers pray to the sun during sunrise to wish for calm waters and good fortune in the new year in Odawara, Kanagawa prefecture, west of Tokyo, Japan, January 1, 2016. REUTERS/Yuya Shino 

The Mississippi River is pictured flowing at 800,000 CFS (cubic feet per second) measured by the U.S. Geological Survey (USGS) in St. Louis, Missouri, December 31, 2015. Missouri and Illinois were bracing for more flooding on Thursday as rain-swollen rivers, some at record heights, overflowed their banks, washing out hundreds of structures and leaving thousands of people displaced from their homes. REUTERS/Kate Munsch 

The Mississippi River is pictured flooding parts of downtown St. Louis, Missouri December 31, 2015. Missouri and Illinois were bracing for more flooding on Thursday as rain-swollen rivers, some at record heights, overflowed their banks, washing out hundreds of structures and leaving thousands of people displaced from their homes. REUTERS/Kate Munsch 

U.S. Geological Survey (USGS) hydro technician Jason Carron assesses the Mississippi River flood waters in St. Louis, Missouri December 31, 2015. Missouri and Illinois were bracing for more flooding on Thursday as rain-swollen rivers, some at record heights, overflowed their banks, washing out hundreds of structures and leaving thousands of people displaced from their homes. REUTERS/Kate Munsch 

People look at the sun during sunrise in Odawara, Kanagawa prefecture, west of Tokyo, Japan, January 1, 2016. REUTERS/Yuya Shino TPX IMAGES OF THE DAY

A vehicle of Mexico's National Migration Institute (INM) enters an immigration office at Iztapalapa neighborhood in Mexico City, Mexico, December 31, 2015. Ethan Couch, the Texas teenager derided for his "affluenza" defense in a deadly drunken-driving case, won a weeks-long in delay in extradition from Mexico, while his mother was in a Los Angeles jail on Thursday after being deported. REUTERS/Edgard Garrido 

French Defence Minister Jean-Yves Le Drian (R) celebrates New Year's eve with French soldiers in France's Charles de Gaulle aircraft carrier in Manama December 31, 2015. REUTERS/Kenzo Tribouillard/Pool