Year | Value | 2021 | 32.324115808755 | 2020 | 32.602269641439 | 2019 | 32.884217466313 | 2018 | 33.131605855374 | 2017 | 33.451827910402 | 2016 | 33.840095588039 | 2015 | 34.199691960449 | 2014 | 34.570210775098 | 2013 | 34.977237800347 | 2012 | 35.423233052108 | 2011 | 35.782675386332 | 2010 | 35.984904343068 | 2009 | 36.177609011973 | 2008 | 36.354223016404 | 2007 | 36.47937611135 | 2006 | 36.586789448842 | 2005 | 36.670136992945 | 2004 | 36.854565563133 | 2003 | 37.030602854989 | 2002 | 37.210146983702 | 2001 | 37.278157184177 | 2000 | 37.35526619128 | 1999 | 37.443333971156 | 1998 | 37.480710045046 | 1997 | 37.780101383538 | 1996 | 38.117549799355 | 1995 | 38.352590763104 | 1994 | 38.406768588844 | 1993 | 38.660627297861 | 1992 | 38.827452391577 | 1991 | 39.077832424609 | 1990 | 39.287720606535 | 1989 | 39.519356569498 | 1988 | 39.781355902903 | 1987 | 40.08071221084 | 1986 | 40.441708137638 | 1985 | 40.680646613015 | 1984 | 40.922937971505 | 1983 | 41.109234736413 | 1982 | 40.959792016321 | 1981 | 41.038484329231 | 1980 | 41.2206993766 | 1979 | 41.332415026058 | 1978 | 41.301317634737 | 1977 | 41.233698201293 | 1976 | 41.245551158548 | 1975 | 41.259583138084 | 1974 | 41.226588541472 | 1973 | 41.152697418997 | 1972 | 41.2992647083 | 1971 | 41.365508247111 | 1970 | 41.239732939295 | 1969 | 41.210769307949 | 1968 | 41.165910819541 | 1967 | 41.233843356925 | 1966 | 41.29694406321 | 1965 | 41.344286210489 | 1964 | 41.42788248148 | 1963 | 41.630699001912 | 1962 | 41.829182248364 | 1961 | 41.687034168734 | 1960 | 41.729973916616 |
|