Year | Value | 2022 | 49.486682251957 | 2021 | 37.900180556436 | 2020 | 32.436268017067 | 2019 | 33.415453811469 | 2018 | 36.691183623731 | 2017 | 33.861084682587 | 2016 | 32.953051238213 | 2015 | 36.000472103002 | 2014 | 39.136102828219 | 2013 | 38.631734645774 | 2012 | 39.472869013281 | 2011 | 38.979895927422 | 2010 | 36.954468303426 | 2009 | 35.838043481675 | 2008 | 42.22535067135 | 2007 | 39.851251742252 | 2006 | 40.561007561421 | 2005 | 39.082303194669 | 2004 | 34.255949118717 | 2003 | 31.745470637862 | 2002 | 32.882494621278 | 2001 | 36.499960395952 | 2000 | 36.632823349331 | 1999 | 30.100568118835 | 1998 | 28.00502656172 | 1997 | 31.199212172399 | 1996 | 29.507714800829 | 1995 | 27.575653527516 | 1994 | 25.832176815109 | 1993 | 24.914401454472 | 1992 | 24.907975005394 | 1991 | 25.477554466735 | 1990 | 26.78431404827 | 1989 | 27.117603881022 | 1988 | 26.283316151861 | 1987 | 26.843501242022 | 1986 | 26.927360732474 | 1985 | 32.116032971942 | 1984 | 32.805648234918 | 1983 | 30.31363331511 | 1982 | 29.762242578669 | 1981 | 31.169412748641 | 1980 | 30.544122904835 | 1979 | 26.663272028151 | 1978 | 26.473668235365 | 1977 | 25.951522594752 | 1976 | 28.379744214236 | 1975 | 30.088810301687 |
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