Year Measure 1960 389.11394 1961 385.47121 1962 411.11935 1963 421.5635 1964 433.90955 1965 445.90145 1966 478.25402 1967 483.95249 1968 496.91227 1969 511.56245 1970 522.19984 1971 547.12781 1972 603.2862 1973 649.9433 1974 656.84779 1975 681.21733 1976 724.48704 1977 776.76572 1978 756.46337 1979 703.54913 1980 715.14898 1981 704.79188 1982 732.22561 1983 757.9531 1984 771.34194 1985 800.28035 1986 844.93935 1987 919.19702 1988 908.41065 1989 926.59348 1990 977.66424 1991 947.7563 1992 961.93224 1993 1004.13715 1994 976.48895 1995 1052.6997 1996 1126.18203 1997 1166.22882 1998 1169.88196 1999 1131.09235 2000 1201.0873 2001 1094.19771 2002 1139.39245 2003 1178.44386 2004 1204.72194 2005 1240.16642 2006 1354.67707 2007 1436.84474 2008 1401.34914 2009 1370.78849 2010 1474.66969 2011 1546.20332 2012 1585.40024 2013 1542.96824 2014 1577.82798 2015 1656.80338