Year Measure 1971 357.97505 1972 360.60044 1973 355.68646 1974 419.13072 1975 449.66125 1976 486.79033 1977 568.07378 1978 569.8215 1979 586.05202 1980 626.37716 1981 635.09273 1982 666.63541 1983 602.74351 1984 629.49419 1985 620.76388 1986 603.02143 1987 602.47025 1988 615.71862 1989 574.63249 1990 619.49223 1991 636.00424 1992 629.22095 1993 573.48764 1994 600.28747 1995 687.96022 1996 709.53806 1997 721.68747 1998 726.97999 1999 641.72347 2000 698.07625 2001 727.86006 2002 698.39528 2003 697.1797 2004 662.33766 2005 679.82254 2006 671.49328 2007 746.94894 2008 676.58709 2009 792.54278 2010 788.06423 2011 821.16825 2012 797.94984 2013 846.45323 2014 891.68862