Tokyo Stock Exchange (TSE) staff member rubs his eyes as he works at the bourse at TSE in Tokyo October 16, 2014. Japan's Nikkei share average tumbled 2.5 percent to a 4-1/2-month low on Thursday after Wall Street dived on deepening worries about weak global demand, while a stronger yen dragged down exporters such as Toyota Motor Corp. REUTERS/Yuya Shino (JAPAN - Tags: BUSINESS)