Year | Value | 2022 | 13.91607718675 | 2021 | 13.84929322815 | 2020 | 12.481991455509 | 2019 | 14.194928882656 | 2018 | 16.127786259137 | 2017 | 16.057028927736 | 2016 | 15.420051415905 | 2015 | 14.216925375057 | 2014 | 20.789477794192 | 2013 | 23.890939663632 | 2012 | 25.694056427927 | 2011 | 26.317417569853 | 2010 | 24.849139499502 | 2009 | 22.8998872468 | 2008 | 28.98328096939 | 2007 | 28.636097506262 | 2006 | 26.582244785913 | 2005 | 19.882483409039 | 2004 | 17.046646348709 | 2003 | 14.48571968613 | 2002 | 12.297067153831 | 2001 | 11.256232612947 | 2000 | 11.015088389058 | 1999 | 10.657470719207 | 1998 | 12.822161458332 | 1997 | 12.582138494101 | 1996 | 12.06921195742 | 1995 | 11.168786642949 | 1994 | 10.199565840514 | 1993 | 7.7987475240831 | 1992 | 8.4805547168471 | 1991 | 8.8843636909961 | 1990 | 9.545988229944 | 1989 | 8.6137724663685 | 1988 | 6.7928271610017 | 1987 | 4.7702873948888 | 1986 | 3.7706194153674 | 1985 | 10.161171087104 | 1984 | 12.157900941905 | 1983 | 12.751069508937 | 1982 | 8.6238202027561 | 1981 | 10.529989680782 | 1980 | 14.185273938335 | 1979 | 14.621962457599 | 1978 | 14.869100555836 | 1977 | 14.672007246713 | 1976 | 16.3310315181 |
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