Year | Value | 2024 | 49.862328050773 | 2023 | 49.849141149239 | 2022 | 49.832851709587 | 2021 | 49.804777907005 | 2020 | 49.772780272997 | 2019 | 49.750562466213 | 2018 | 49.731585892981 | 2017 | 49.712029086269 | 2016 | 49.692652971416 | 2015 | 49.674717243729 | 2014 | 49.657386423171 | 2013 | 49.640615106468 | 2012 | 49.625081058055 | 2011 | 49.610525184341 | 2010 | 49.595928595666 | 2009 | 49.580329652949 | 2008 | 49.564279292351 | 2007 | 49.548898106932 | 2006 | 49.534699073431 | 2005 | 49.52172299397 | 2004 | 49.509648352113 | 2003 | 49.498661112485 | 2002 | 49.494120115682 | 2001 | 49.495632931035 | 2000 | 49.497105198566 | 1999 | 49.4987642748 | 1998 | 49.500951525758 | 1997 | 49.50383905263 | 1996 | 49.507503289569 | 1995 | 49.512119072293 | 1994 | 49.517871064615 | 1993 | 49.524468356264 | 1992 | 49.532055090289 | 1991 | 49.540798057314 | 1990 | 49.550876207057 | 1989 | 49.562210732055 | 1988 | 49.575898314011 | 1987 | 49.591912326832 | 1986 | 49.608663941648 | 1985 | 49.626239542241 | 1984 | 49.644792636018 | 1983 | 49.664081628225 | 1982 | 49.684023373715 | 1981 | 49.715276460867 | 1980 | 49.759681125102 | 1979 | 49.810673756636 | 1978 | 49.869812011235 | 1977 | 49.934296931193 | 1976 | 50.001631122691 | 1975 | 50.070180053261 |
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