Year | Value | 2022 | 28.3 | 2021 | 28.605 | 2020 | 28.91 | 2019 | 29.214 | 2018 | 29.517 | 2017 | 29.819 | 2016 | 30.12 | 2015 | 30.421 | 2014 | 30.72 | 2013 | 31.018 | 2012 | 31.315 | 2011 | 31.611 | 2010 | 31.906 | 2009 | 32.201 | 2008 | 32.498 | 2007 | 32.797 | 2006 | 33.097 | 2005 | 33.399 | 2004 | 33.701 | 2003 | 34.006 | 2002 | 34.311 | 2001 | 34.618 | 2000 | 34.735 | 1999 | 34.821 | 1998 | 34.908 | 1997 | 34.995 | 1996 | 35.082 | 1995 | 35.169 | 1994 | 35.256 | 1993 | 35.344 | 1992 | 35.431 | 1991 | 35.518 | 1990 | 36.921 | 1989 | 38.55 | 1988 | 40.202 | 1987 | 41.882 | 1986 | 43.578 | 1985 | 45.29 | 1984 | 47.01 | 1983 | 48.743 | 1982 | 50.476 | 1981 | 52.207 | 1980 | 53.241 | 1979 | 54.065 | 1978 | 54.885 | 1977 | 55.703 | 1976 | 56.516 | 1975 | 57.329 | 1974 | 58.136 | 1973 | 58.939 | 1972 | 59.736 | 1971 | 60.53 | 1970 | 61.317 | 1969 | 61.552 | 1968 | 61.619 | 1967 | 61.686 | 1966 | 61.753 | 1965 | 61.82 | 1964 | 61.887 | 1963 | 61.954 | 1962 | 62.021 | 1961 | 62.088 | 1960 | 62.154 |
|