Year Measure 1971 221.84889 1972 240.13858 1973 248.67079 1974 260.68752 1975 295.58835 1976 316.77967 1977 331.39263 1978 351.40969 1979 378.52778 1980 437.33146 1981 449.26561 1982 462.37958 1983 429.43812 1984 419.4207 1985 405.70148 1986 375.86561 1987 341.401 1988 349.81534 1989 365.42261 1990 380.7611 1991 384.86477 1992 399.68818 1993 418.96059 1994 452.15687 1995 497.50367 1996 524.43368 1997 560.81417 1998 555.90167 1999 535.84875 2000 588.17758 2001 449.19263 2002 528.73588 2003 539.9023 2004 531.07789 2005 569.2204 2006 700.31166 2007 561.01609 2008 586.82074 2009 601.30859 2010 644.49859 2011 669.81973 2012 757.99795 2013 750.28374 2014 788.80435