Year Measure 1971 14.34847 1972 15.89301 1973 15.81587 1974 19.1817 1975 21.4421 1976 18.3269 1977 21.72265 1978 31.749 1979 38.67313 1980 46.15895 1981 52.2656 1982 61.41499 1983 66.08272 1984 71.43052 1985 79.74562 1986 92.04165 1987 104.33886 1988 119.51937 1989 137.49401 1990 162.50285 1991 177.93151 1992 194.30559 1993 212.8201 1994 240.01101 1995 263.58939 1996 297.18155 1997 331.29799 1998 331.12714 1999 357.02549 2000 390.37455 2001 411.3162 2002 417.20753 2003 428.39742 2004 473.67648 2005 499.71609 2006 514.86654 2007 544.71208 2008 568.39605 2009 592.15642 2010 634.17609 2011 678.64429 2012 732.10235 2013 773.29385 2014 811.90018