Year Index 2010=1, Trend 1970-01-01 0.189437862436273 1971-01-01 0.208056906746386 1972-01-01 0.215864484216250 1973-01-01 0.220202409468739 1974-01-01 0.259490272627946 1975-01-01 0.325955297236243 1976-01-01 0.362919039846905 1977-01-01 0.402154444896135 1978-01-01 0.402292621659932 1979-01-01 0.400842411409846 1980-01-01 0.431351079053442 1981-01-01 0.442362816352350 1982-01-01 0.476974016631263 1983-01-01 0.528269506613699 1984-01-01 0.560776888419879 1985-01-01 0.573049345590041 1986-01-01 0.589220200546163 1987-01-01 0.599908093420859 1988-01-01 0.589637569236517 1989-01-01 0.611559109515400 1990-01-01 0.634556947397948 1991-01-01 0.678723051777453 1992-01-01 0.722971345500607 1993-01-01 0.769336587055450 1994-01-01 0.790222410263049 1995-01-01 0.750773154729134 1996-01-01 0.751101867762011 1997-01-01 0.773917914131965 1998-01-01 0.770951323927282 1999-01-01 0.789417505599064 2000-01-01 0.820426225090274 2001-01-01 0.870480151947334 2002-01-01 0.869037591731464 2003-01-01 0.879702830196588 2004-01-01 0.883596579959910 2005-01-01 0.881524470027068 2006-01-01 0.896757247819392 2007-01-01 0.937961345749420 2008-01-01 0.968519832599856 2009-01-01 0.995672122901729 2010-01-01 1.000000000000000