Year | Value | 2022 | 51.030962834057 | 2021 | 51.059246421331 | 2020 | 51.089798929538 | 2019 | 51.11472673578 | 2018 | 51.134265493892 | 2017 | 51.153167535707 | 2016 | 51.167690134385 | 2015 | 51.176880045603 | 2014 | 51.183039794374 | 2013 | 51.18633611991 | 2012 | 51.187501484475 | 2011 | 51.18708533965 | 2010 | 51.185599936284 | 2009 | 51.182249115327 | 2008 | 51.177535471655 | 2007 | 51.172802111892 | 2006 | 51.167530373494 | 2005 | 51.161916508481 | 2004 | 51.156606509831 | 2003 | 51.151067038846 | 2002 | 51.145345759676 | 2001 | 51.139162889648 | 2000 | 51.127825884033 | 1999 | 51.110415400855 | 1998 | 51.094854844615 | 1997 | 51.079839825814 | 1996 | 51.061996365842 | 1995 | 51.044074555409 | 1994 | 51.025646332094 | 1993 | 51.007685996807 | 1992 | 50.989953113294 | 1991 | 50.969855773026 | 1990 | 50.948760306727 | 1989 | 50.930699706725 | 1988 | 50.917731121984 | 1987 | 50.907753637243 | 1986 | 50.900068455481 | 1985 | 50.895954471455 | 1984 | 50.895189464617 | 1983 | 50.897161397278 | 1982 | 50.899772320441 | 1981 | 50.902762819702 | 1980 | 50.907435856412 | 1979 | 50.913038408905 | 1978 | 50.91965494281 | 1977 | 50.926931946784 | 1976 | 50.933797376916 | 1975 | 50.940432365859 | 1974 | 50.946444326149 | 1973 | 50.950011256141 | 1972 | 50.9515713997 | 1971 | 50.952559331798 | 1970 | 50.954551873177 | 1969 | 50.95903181062 | 1968 | 50.965834553901 | 1967 | 50.976378302065 | 1966 | 50.990779454266 | 1965 | 51.008430519831 | 1964 | 51.028525270587 | 1963 | 51.049096532188 | 1962 | 51.072706718096 | 1961 | 51.103250283498 | 1960 | 51.139909826471 |
|