Year Index 2010=1, Trend 1970-01-01 0.411511704603412 1971-01-01 0.446296235986274 1972-01-01 0.470353418320187 1973-01-01 0.499428615546957 1974-01-01 0.585331423767412 1975-01-01 0.623137909690409 1976-01-01 0.717373236144641 1977-01-01 0.732701990157170 1978-01-01 0.732484233161330 1979-01-01 0.724639040472752 1980-01-01 0.740165220248592 1981-01-01 0.743835199080080 1982-01-01 0.755801484983316 1983-01-01 0.765250094839238 1984-01-01 0.777149947940922 1985-01-01 0.800639941480948 1986-01-01 0.809480244167640 1987-01-01 0.814866664759242 1988-01-01 0.818382426688920 1989-01-01 0.839082262935007 1990-01-01 0.868349002030177 1991-01-01 0.888762488757913 1992-01-01 0.924658709149530 1993-01-01 0.963388156491647 1994-01-01 0.979958917978155 1995-01-01 0.978483137246734 1996-01-01 0.970254029537882 1997-01-01 0.938845316974948 1998-01-01 0.931439169078799 1999-01-01 0.942724041551516 2000-01-01 0.917486133853107 2001-01-01 0.950413479888289 2002-01-01 0.964707722810276 2003-01-01 0.965764975382944 2004-01-01 0.948831034333811 2005-01-01 0.948421901832954 2006-01-01 0.958890218222703 2007-01-01 0.956743111585542 2008-01-01 0.987228611164592 2009-01-01 1.016540396678840 2010-01-01 1.000000000000000