Year | Value | 2022 | 49.519544048548 | 2021 | 49.495639259983 | 2020 | 49.471404184502 | 2019 | 49.447934913675 | 2018 | 49.42591563156 | 2017 | 49.402869830734 | 2016 | 49.379382398883 | 2015 | 49.355175784656 | 2014 | 49.329042069217 | 2013 | 49.302144600349 | 2012 | 49.274117075359 | 2011 | 49.244805224377 | 2010 | 49.25216057809 | 2009 | 49.298753898028 | 2008 | 49.347102506964 | 2007 | 49.398280325164 | 2006 | 49.450339348801 | 2005 | 49.500292959252 | 2004 | 49.546271555047 | 2003 | 49.585765997987 | 2002 | 49.619430604012 | 2001 | 49.619842152153 | 2000 | 49.585420427901 | 1999 | 49.546883149982 | 1998 | 49.507333064716 | 1997 | 49.472089282266 | 1996 | 49.437881955683 | 1995 | 49.400712335277 | 1994 | 49.363761145347 | 1993 | 49.327756170414 | 1992 | 49.292298038512 | 1991 | 49.256346514899 | 1990 | 49.220052155486 | 1989 | 49.183224587264 | 1988 | 49.190637164451 | 1987 | 49.197195892005 | 1986 | 49.13213520812 | 1985 | 49.043438553002 | 1984 | 48.95340129638 | 1983 | 48.859486859045 | 1982 | 48.762248244575 | 1981 | 48.664804449186 | 1980 | 48.570583864515 | 1979 | 48.483886684555 | 1978 | 48.409233514994 | 1977 | 48.353874782562 | 1976 | 48.322984757843 | 1975 | 48.341452945376 | 1974 | 48.403363423268 | 1973 | 48.47789959141 | 1972 | 48.56405970317 | 1971 | 48.652189323515 | 1970 | 48.729251284351 | 1969 | 48.78792209317 | 1968 | 48.830301779804 | 1967 | 48.866213175272 | 1966 | 48.905847667278 | 1965 | 48.952322447244 | 1964 | 49.004690181442 | 1963 | 49.064406598607 | 1962 | 49.132390946423 | 1961 | 49.203214064468 | 1960 | 49.266001934391 |
|