Year | Value | 2021 | 38.809 | 2020 | 39.271 | 2019 | 39.725 | 2018 | 40.236 | 2017 | 40.81 | 2016 | 41.377 | 2015 | 42.02 | 2014 | 42.676 | 2013 | 43.282 | 2012 | 43.86 | 2011 | 44.364 | 2010 | 44.97 | 2009 | 45.495 | 2008 | 45.889 | 2007 | 46.29 | 2006 | 46.643 | 2005 | 46.944 | 2004 | 47.099 | 2003 | 47.226 | 2002 | 47.448 | 2001 | 47.574 | 2000 | 47.647 | 1999 | 47.773 | 1998 | 48.009 | 1997 | 48.412 | 1996 | 48.86 | 1995 | 49.185 | 1994 | 49.55 | 1993 | 49.893 | 1992 | 50.374 | 1991 | 50.926 | 1990 | 51.344 | 1989 | 51.699 | 1988 | 51.973 | 1987 | 52.146 | 1986 | 52.19 | 1985 | 52.136 | 1984 | 51.935 | 1983 | 51.61 | 1982 | 51.307 | 1981 | 51.109 | 1980 | 50.892 | 1979 | 50.732 | 1978 | 50.616 | 1977 | 50.523 | 1976 | 50.514 | 1975 | 50.469 | 1974 | 50.472 | 1973 | 50.467 | 1972 | 50.474 | 1971 | 50.698 | 1970 | 51.267 | 1969 | 51.353 | 1968 | 51.348 | 1967 | 51.314 | 1966 | 51.295 | 1965 | 51.282 | 1964 | 51.282 | 1963 | 51.323 | 1962 | 51.316 | 1961 | 51.282 | 1960 | 51.026 |
|