Year | Value | 2022 | 51.096643045826 | 2021 | 51.102552770967 | 2020 | 51.107363662008 | 2019 | 51.114209102058 | 2018 | 51.124890642742 | 2017 | 51.140493195897 | 2016 | 51.15821622547 | 2015 | 51.179324333669 | 2014 | 51.197658144321 | 2013 | 51.208234523597 | 2012 | 51.218481610317 | 2011 | 51.227991329454 | 2010 | 51.233796650676 | 2009 | 51.239528589718 | 2008 | 51.248895170931 | 2007 | 51.264360729882 | 2006 | 51.280760995454 | 2005 | 51.298093707054 | 2004 | 51.31881185312 | 2003 | 51.337735642386 | 2002 | 51.353018285405 | 2001 | 51.361037440485 | 2000 | 51.362626774761 | 1999 | 51.363717146684 | 1998 | 51.365245840481 | 1997 | 51.368746077048 | 1996 | 51.374601474886 | 1995 | 51.382890346665 | 1994 | 51.394708203732 | 1993 | 51.410994942194 | 1992 | 51.430281556646 | 1991 | 51.450927737422 | 1990 | 51.472353629037 | 1989 | 51.492305662428 | 1988 | 51.510062761626 | 1987 | 51.526485602592 | 1986 | 51.54250908241 | 1985 | 51.556179008957 | 1984 | 51.566419015204 | 1983 | 51.575788588139 | 1982 | 51.584805600772 | 1981 | 51.593005121546 | 1980 | 51.612134701997 | 1979 | 51.629312057639 | 1978 | 51.633675897413 | 1977 | 51.639657733661 | 1976 | 51.647258280091 | 1975 | 51.655347846953 | 1974 | 51.667764071573 | 1973 | 51.683058048542 | 1972 | 51.698269709197 | 1971 | 51.717739047599 | 1970 | 51.739586669813 | 1969 | 51.758491781419 | 1968 | 51.778154833597 | 1967 | 51.803374162553 | 1966 | 51.832104086398 | 1965 | 51.862899575991 | 1964 | 51.89566065966 | 1963 | 51.92928881469 | 1962 | 51.963476894697 | 1961 | 51.996469652059 | 1960 | 52.02810366438 |
|