Year Measure 1971 1297.80239 1972 1311.96042 1973 1416.44662 1974 1351.3637 1975 1439.39394 1976 1610.00443 1977 1804.87379 1978 1950.72309 1979 2003.16449 1980 2156.58391 1981 2229.61763 1982 2361.47782 1983 2624.83396 1984 2786.45399 1985 2918.33144 1986 3196.79253 1987 3845.35436 1988 4072.07335 1989 3936.724 1990 4177.9297 1991 4401.25174 1992 4507.88725 1993 4698.69514 1994 4835.47072 1995 4849.82375 1996 4915.70197 1997 4968.48659 1998 5325.73315 1999 5268.14501 2000 5446.66167 2001 5549.94564 2002 5647.89965 2003 5713.88245 2004 5782.56063 2005 5878.44185 2006 5882.8076 2007 5907.34931 2008 5883.03774 2009 5950.83754 2010 5973.34928 2011 5959.89592 2012 6031.24432 2013 5941.1609 2014 6083.26994