Year | Value | 2014 | 36.550777724682 | 2013 | 37.142679851986 | 2012 | 35.86729549956 | 2011 | 35.663619619339 | 2010 | 40.748643216772 | 2009 | 43.78723489815 | 2008 | 48.292006599755 | 2007 | 50.428723143225 | 2006 | 46.051085524628 | 2005 | 46.480482141872 | 2004 | 45.468662179234 | 2003 | 47.399519226697 | 2002 | 43.874093649933 | 2001 | 46.584305320062 | 2000 | 46.840521435319 | 1999 | 50.103425515311 | 1998 | 49.291838119621 | 1997 | 50.962759599851 | 1996 | 53.472050107363 | 1995 | 55.426377254336 | 1994 | 55.716470536259 | 1993 | 57.725375655334 | 1992 | 56.920790165522 | 1991 | 61.225157944548 | 1990 | 65.939593772374 | 1989 | 66.662570794326 | 1988 | 66.484142487086 | 1987 | 67.183083412555 | 1986 | 68.055470822627 | 1985 | 68.900462027383 | 1984 | 67.242586116356 | 1983 | 67.979958908793 | 1982 | 68.298515071617 | 1981 | 69.881658334021 | 1980 | 72.74581902654 | 1979 | 74.070371473323 | 1978 | 75.243690250356 | 1977 | 74.76454066249 | 1976 | 73.889490190278 | 1975 | 73.592350868909 | 1974 | 75.892627641476 | 1973 | 73.302839356895 | 1972 | 71.158557794427 | 1971 | 69.977791797961 |
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