Year | Value | 2021 | 9.0258143034622 | 2020 | 8.8911337467237 | 2019 | 9.1092244677157 | 2018 | 9.2820730470368 | 2017 | 9.4746355062254 | 2016 | 9.7015614451426 | 2015 | 9.6553146565126 | 2014 | 9.7871732488216 | 2013 | 9.7315960483992 | 2012 | 9.9992495115056 | 2011 | 10.15706203453 | 2010 | 10.352650356548 | 2009 | 10.342033141866 | 2008 | 10.547664698191 | 2007 | 10.371197882869 | 2006 | 10.368181964665 | 2005 | 10.293784971806 | 2004 | 10.403256841878 | 2003 | 10.325849371612 | 2002 | 10.315427988651 | 2001 | 10.376730396961 | 2000 | 10.615243361869 | 1999 | 10.46384907954 | 1998 | 10.470779320173 | 1997 | 10.582410096883 | 1996 | 10.533881623968 | 1995 | 10.442151860186 | 1994 | 10.562743433896 | 1993 | 10.929961003199 | 1992 | 11.190679862279 | 1991 | 11.366799736328 | 1990 | 11.713427504523 | 1989 | 11.681607090157 | 1988 | 11.916518347827 | 1987 | 11.867119116086 | 1986 | 11.943364082412 | 1985 | 12.015654829447 | 1984 | 12.198497854861 | 1983 | 12.370798236842 | 1982 | 12.70674437255 | 1981 | 12.812424018822 | 1980 | 13.085602825498 | 1979 | 13.168749200001 | 1978 | 13.440946093063 | 1977 | 13.684081179035 | 1976 | 14.013070792555 | 1975 | 14.152730070224 | 1974 | 14.63334061505 | 1973 | 14.747614542859 | 1972 | 15.368502158974 | 1971 | 16.041686906673 | 1970 | 16.248166943328 | 1969 | 16.966110218481 | 1968 | 17.396393391897 | 1967 | 17.856751086942 | 1966 | 18.32405560432 | 1965 | 18.593375117377 | 1964 | 19.167752118399 | 1963 | 18.970147230255 | 1962 | 18.875089394346 | 1961 | 19.001473334533 | 1960 | 18.832397775979 |
|