Year | Value | 2021 | 39.976175349428 | 2020 | 39.976175349428 | 2019 | 39.976175349428 | 2018 | 39.976175349428 | 2017 | 39.976175349428 | 2016 | 39.976175349428 | 2015 | 39.895965692503 | 2014 | 39.895171537484 | 2013 | 39.736340533672 | 2012 | 39.457592121982 | 2011 | 39.179637865311 | 2010 | 39.100222363405 | 2009 | 38.941391359593 | 2008 | 38.858799237611 | 2007 | 38.858799237611 | 2006 | 38.858005082592 | 2005 | 38.858005082592 | 2004 | 38.778589580686 | 2003 | 38.778589580686 | 2002 | 38.69917407878 | 2001 | 38.69917407878 | 2000 | 38.619758576874 | 1999 | 38.619758576874 | 1998 | 38.619758576874 | 1997 | 38.619758576874 | 1996 | 38.460927573062 | 1995 | 38.476810673444 | 1994 | 38.452986022872 | 1993 | 38.437102922491 | 1992 | 38.413278271919 | 1991 | 38.397395171537 | 1990 | 38.357687420584 | 1989 | 38.317979669631 | 1988 | 38.30209656925 | 1987 | 38.282242693774 | 1986 | 38.282242693774 | 1985 | 38.242534942821 | 1984 | 38.238564167725 | 1983 | 38.238564167725 | 1982 | 38.238564167725 | 1981 | 38.238564167725 | 1980 | 38.238564167725 | 1979 | 38.238564167725 | 1978 | 38.238564167725 | 1977 | 38.198856416773 | 1976 | 38.198856416773 | 1975 | 38.119440914867 | 1974 | 38.043823436011 | 1973 | 38.023809523809 | 1972 | 38.015873015873 | 1971 | 38.015873015873 | 1970 | 38.015873015873 | 1969 | 38.015873015873 | 1968 | 38.015873015873 | 1967 | 38.015873015873 | 1966 | 38.015873015873 | 1965 | 38.015873015873 | 1964 | 38.015873015873 | 1963 | 38.015873015873 | 1962 | 38.015873015873 | 1961 | 38.015873015873 |
|