1959 	11.79848
1960 	13.08092
1961 	13.33741
1962 	14.07024
1963	14.94963
1964	16.15879
1965 	16.37864
1966 	19.52978
1967 	19.30993
1968 	21.10536
1969 	22.20459
1970 	27.99391
1971 	27.15116
1972 	29.38628
1973 	30.4
1974 	27.6
1975 	30.5
1976 	33.2
1977 	33.2
1978 	32.5
1979 	34.5
1980 	32.3
1981 	31.7
1982 	30.8
1983 	31.8
1984 	33.7
1985 	32.1
1986 	34.6
1987 	33.3
1988 	35.4
1989 	34.3
1990 	35.32216
1991 	33.8162
1992 	34.7359
1993 	36.22353
1994 	38.08857
1995 	38.70414
1996 	41.82231
1997 	41.92125
1998 	42.21071
1999 	42.96186
2000 	42.51483
2001 	43.8669
2002 	42.98384
2003 	44.32125
2004 	44.64735
2005 	43.95117
2006 	44.49712
2007 	46.23759
2008 	45.38018
2009 	43.89254
2010 	46.23026
2011 	45.51208
2012 	45.0211
2013 	44.94781
2014 	44.88919
2015 	45.30323
2016 	44.46048
2017 	43.76064