Year Measure 1960 975.02575 1961 1046.41511 1962 1143.60513 1963 1266.35058 1964 1353.31449 1965 1446.73959 1966 1573.20208 1967 1693.25432 1968 1823.39875 1969 1934.81446 1970 2072.91277 1971 2152.77394 1972 2295.49306 1973 2457.72684 1974 2537.28539 1975 2476.36221 1976 2710.45794 1977 2776.81813 1978 2891.04419 1979 3040.95961 1980 3104.85458 1981 3096.93474 1982 3132.77122 1983 3134.39234 1984 3304.32741 1985 3391.66963 1986 3490.34312 1987 3662.66656 1988 3825.91778 1989 4007.17952 1990 4144.90744 1991 4224.74011 1992 4310.53797 1993 4303.64531 1994 4439.31925 1995 4597.8926 1996 4658.70016 1997 4791.28525 1998 4955.72194 1999 5079.49241 2000 5299.85648 2001 5406.49172 2002 5539.70384 2003 5652.51954 2004 5687.99757 2005 5731.10156 2006 5833.4673 2007 5804.32596 2008 5757.96061 2009 5368.39057 2010 5493.71104 2011 5514.80361 2012 5397.74148 2013 5159.18366 2014 5002.40668