Year | Value | 2022 | 8.8651157090929 | 2021 | 8.458596465181 | 2020 | 5.6461887627507 | 2019 | 10.235912722072 | 2018 | 10.671970375041 | 2017 | 10.963175720385 | 2016 | 11.664561897821 | 2015 | 12.945117157486 | 2014 | 14.870487736862 | 2013 | 14.887288108621 | 2012 | 16.889570130252 | 2011 | 16.496973995966 | 2010 | 21.428327744128 | 2009 | 20.957884834314 | 2008 | 21.213174993947 | 2007 | 20.741809223725 | 2006 | 21.162377994676 | 2005 | 20.206585853211 | 2004 | 21.102772915631 | 2003 | 20.274952816946 | 2002 | 20.266433006359 | 2001 | 22.038405758702 | 2000 | 22.171749525895 | 1999 | 22.762145518412 | 1998 | 21.886617661867 | 1997 | 21.672462391211 | 1996 | 22.604279348265 | 1995 | 20.333110290732 | 1994 | 21.132174852796 | 1993 | 19.590126196793 | 1992 | 21.861546049039 | 1991 | 22.234982882205 | 1990 | 23.434262291311 | 1989 | 22.866767307053 | 1988 | 22.75592786492 | 1987 | 22.882776475455 | 1986 | 19.288027660775 | 1985 | 23.669550349135 | 1984 | 25.711120376212 | 1983 | 26.666786612325 | 1982 | 22.614682282151 | 1981 | 24.959152680906 | 1980 | 25.329128548255 | 1979 | 27.422992190617 | 1978 | 23.595959672384 | 1977 | 22.414832979383 | 1976 | 25.8199689703 |
|