Year Measure 1971 54.74026 1972 55.84212 1973 60.82697 1974 61.58075 1975 64.14937 1976 66.54696 1977 68.18759 1978 69.69649 1979 73.30193 1980 80.43762 1981 67.55772 1982 100.96377 1983 96.05981 1984 144.09138 1985 109.03434 1986 170.01471 1987 173.39915 1988 162.24299 1989 164.20997 1990 168.00132 1991 178.64463 1992 171.51494 1993 155.18177 1994 139.57775 1995 146.46754 1996 149.3459 1997 124.89578 1998 107.26752 1999 66.95694 2000 92.69228 2001 101.63441 2002 112.11618 2003 111.63394 2004 102.62273 2005 114.3013 2006 122.58075 2007 122.22584 2008 131.94231 2009 141.05327 2010 136.54933 2011 143.81538 2012 208.91953 2013 207.30763 2014 197.28599