Year | Value | 2022 | 50.644915388872 | 2021 | 50.606934092346 | 2020 | 50.559406755112 | 2019 | 50.513996066498 | 2018 | 50.476135965677 | 2017 | 50.439781151211 | 2016 | 50.404114715916 | 2015 | 50.369149643716 | 2014 | 50.335577692715 | 2013 | 50.302284438161 | 2012 | 50.269173698449 | 2011 | 50.250223702129 | 2010 | 50.232779746203 | 2009 | 50.202772422357 | 2008 | 50.173991936617 | 2007 | 50.145245049925 | 2006 | 50.115447446373 | 2005 | 50.085980980222 | 2004 | 50.043183082375 | 2003 | 49.991141672613 | 2002 | 49.94533194658 | 2001 | 49.902187296745 | 2000 | 49.860511884994 | 1999 | 49.818855960017 | 1998 | 49.777672099259 | 1997 | 49.739630305584 | 1996 | 49.705976851827 | 1995 | 49.677279203521 | 1994 | 49.663720596675 | 1993 | 49.660856485666 | 1992 | 49.656644559411 | 1991 | 49.652162689077 | 1990 | 49.647518733065 | 1989 | 49.643851869508 | 1988 | 49.640962186638 | 1987 | 49.636424917409 | 1986 | 49.62909903317 | 1985 | 49.619252946593 | 1984 | 49.597281663248 | 1983 | 49.585264698707 | 1982 | 49.604921964152 | 1981 | 49.637220957733 | 1980 | 49.673449519896 | 1979 | 49.714885357995 | 1978 | 49.762857009476 | 1977 | 49.820861417855 | 1976 | 49.88364245654 | 1975 | 49.908494846833 | 1974 | 49.892501776197 | 1973 | 49.871917124999 | 1972 | 49.846883958867 | 1971 | 49.815188612979 | 1970 | 49.780520838039 | 1969 | 49.743202767274 | 1968 | 49.700428609972 | 1967 | 49.638907499693 | 1966 | 49.544754287342 | 1965 | 49.502477070107 | 1964 | 49.538264420993 | 1963 | 49.582845402852 | 1962 | 49.632486201884 | 1961 | 49.682536010647 | 1960 | 49.737109122775 |
|