Year | Value | 2021 | 79.028350520917 | 2020 | 78.961629940223 | 2019 | 79.800023683837 | 2018 | 79.498267071825 | 2017 | 79.381568207893 | 2016 | 79.308519469243 | 2015 | 78.935303352019 | 2014 | 79.21439997479 | 2013 | 78.766199625065 | 2012 | 78.43471065626 | 2011 | 78.356007215584 | 2010 | 77.882701854923 | 2009 | 77.616084439974 | 2008 | 77.394044270041 | 2007 | 77.110413910703 | 2006 | 76.826732198967 | 2005 | 76.395249871235 | 2004 | 76.219343105964 | 2003 | 75.6606937229 | 2002 | 75.547172134989 | 2001 | 75.401690196005 | 2000 | 75.010580542597 | 1999 | 74.725080067749 | 1998 | 74.466959453724 | 1997 | 74.208865912381 | 1996 | 73.781646842947 | 1995 | 73.463434057194 | 1994 | 73.29211484754 | 1993 | 72.980179393231 | 1992 | 72.827887732422 | 1991 | 72.505801027722 | 1990 | 72.398952011676 | 1989 | 72.331443502122 | 1988 | 72.17307268255 | 1987 | 71.99594423171 | 1986 | 71.711407981215 | 1985 | 71.38399759408 | 1984 | 71.222628104387 | 1983 | 70.85328060984 | 1982 | 70.778696235287 | 1981 | 70.428066267355 | 1980 | 70.148566604024 | 1979 | 70.012516079723 | 1978 | 69.692145384697 | 1977 | 69.561456947592 | 1976 | 69.172423024429 | 1975 | 68.872079097485 | 1974 | 68.848583437398 | 1973 | 68.56230436221 | 1972 | 68.464118398113 | 1971 | 68.140905112567 | 1970 | 68.037699230159 | 1969 | 67.62541457932 | 1968 | 67.782620497557 | 1967 | 67.895120253479 | 1966 | 67.752719396924 | 1965 | 67.537317150579 | 1964 | 67.472698119655 | 1963 | 66.983245620802 | 1962 | 66.870218380002 | 1961 | 66.959244774899 | 1960 | 66.570167762229 |
|