Year | Value | 2021 | 23.112437562789 | 2020 | 23.299456060684 | 2019 | 23.644962165025 | 2018 | 23.787368182038 | 2017 | 24.529740774323 | 2016 | 24.695894820283 | 2015 | 24.573100562181 | 2014 | 24.54569080986 | 2013 | 24.351772255653 | 2012 | 25.129445632834 | 2011 | 24.863967352165 | 2010 | 25.055498890022 | 2009 | 25.061163919304 | 2008 | 25.036086607859 | 2007 | 25.216886057182 | 2006 | 25.492003687523 | 2005 | 25.87308902202 | 2004 | 26.092792179174 | 2003 | 26.075198814126 | 2002 | 25.867665918564 | 2001 | 26.205568482709 | 2000 | 26.85370741483 | 1999 | 26.956190933846 | 1998 | 27.398686528912 | 1997 | 28.602034278392 | 1996 | 28.932404292808 | 1995 | 28.121496075605 | 1994 | 29.645202626942 | 1993 | 29.997597308986 | 1992 | 30.436088419029 | 1991 | 30.550216242191 | 1990 | 30.704388915586 | 1989 | 31.058785840141 | 1988 | 31.188931603396 | 1987 | 31.202947300977 | 1986 | 31.164904693256 | 1985 | 31.162902450745 | 1984 | 31.337097549255 | 1983 | 31.21959033298 | 1982 | 31.163656749289 | 1981 | 31.17166539863 | 1980 | 31.149017959037 | 1979 | 31.184689914721 | 1978 | 31.309430865013 | 1977 | 31.288785682828 | 1976 | 31.340953219769 | 1975 | 31.665432419991 | 1974 | 31.851925962982 | 1973 | 32.122133738845 | 1972 | 32.59033974949 | 1971 | 32.692384649246 | 1970 | 31.393813277842 | 1969 | 32.178158389691 | 1968 | 31.397815038617 | 1967 | 31.493857297211 | 1966 | 31.031653927728 | 1965 | 31.946056264756 | 1964 | 31.85201488655 | 1963 | 32.424266677338 | 1962 | 32.606346792589 | 1961 | 32.50630277322 |
|