Year Measure 1960 2614.2823 1961 2871.04324 1962 2895.08603 1963 2978.67527 1964 3074.3506 1965 2974.73555 1966 2914.55745 1967 2918.22431 1968 2992.73406 1969 3796.05545 1970 6471.39964 1971 7001.52355 1972 7650.48748 1973 9895.58066 1974 9962.40864 1975 9588.07959 1976 10002.08945 1977 10631.24721 1978 10986.99544 1979 11841.31836 1980 12680.9212 1981 12918.46331 1982 14038.31352 1983 14642.77124 1984 15239.38358 1985 14771.85642 1986 15350.76898 1987 15268.9143 1988 16353.00713 1989 16424.62785 1990 16148.27372 1991 15931.13962 1992 16099.9322 1993 16737.13148 1994 17066.32183 1995 17396.4736 1996 17358.58037 1997 18957.83541 1998 21321.16024 1999 24522.22755 2000 26201.52558 2001 26950.39443 2002 27896.89868 2003 27666.38689 2004 28215.45225 2005 27988.02968 2006 31328.3868 2007 36852.54489 2008 50063.95433 2009 51259.18763 2010 51439.90869 2011 52373.87701 2012 53202.83366 2013 54799.17471 2014 53832.47909