| Year | Value | | 2014 | -33.395272192699 | | 2013 | -34.830977379812 | | 2012 | -37.20267307484 | | 2011 | -65.925908740348 | | 2010 | -67.530835676766 | | 2009 | -63.61753491206 | | 2008 | -65.057590366305 | | 2007 | -76.685341897876 | | 2006 | -78.828557553738 | | 2005 | -79.910870999096 | | 2004 | -88.105289970619 | | 2003 | -97.063188091651 | | 2002 | -83.963484658786 | | 2001 | -86.069069047155 | | 2000 | -106.18185850562 | | 1999 | -93.5725229323 | | 1998 | -116.77320532338 | | 1997 | -117.80360953301 | | 1996 | -140.95067718598 | | 1995 | -134.80938756497 | | 1994 | -139.21349209494 | | 1993 | -161.58332176698 | | 1992 | -165.63617981307 | | 1991 | -160.82759144913 | | 1990 | -170.92881229881 | | 1989 | -149.87426796181 | | 1988 | -149.92856289263 | | 1987 | -132.93621387747 | | 1986 | -87.840674712034 | | 1985 | -127.74244669766 | | 1984 | -140.46883994783 | | 1983 | -210.56005430411 | | 1982 | -158.56023239395 | | 1981 | -85.329900412441 | | 1980 | -112.19159727995 | | 1979 | -361.61780617475 | | 1978 | -743.07443083031 | | 1977 | -785.9692026663 | | 1976 | -933.96981485207 | | 1975 | -969.61913355822 | | 1974 | -1,198.3563239999 | | 1973 | -1,400.6465079833 | | 1972 | -1,538.4661359585 | | 1971 | -1,337.5665861628 |
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