Year | Value | 2024 | 50.288589798622 | 2023 | 50.294395375282 | 2022 | 50.295377061286 | 2021 | 50.297858401758 | 2020 | 50.304364574282 | 2019 | 50.304102072522 | 2018 | 50.294716105704 | 2017 | 50.284139717446 | 2016 | 50.2354595472 | 2015 | 50.145318034574 | 2014 | 50.048207875733 | 2013 | 49.945130079059 | 2012 | 49.873098308467 | 2011 | 49.834445016585 | 2010 | 49.79391755175 | 2009 | 49.754185697284 | 2008 | 49.716751919175 | 2007 | 49.68067482972 | 2006 | 49.645557773174 | 2005 | 49.611087302043 | 2004 | 49.578787127349 | 2003 | 49.578622599588 | 2002 | 49.520059113688 | 2001 | 49.376302035744 | 2000 | 49.245075361886 | 1999 | 49.127093843354 | 1998 | 49.086231627361 | 1997 | 49.120972395363 | 1996 | 49.157595465501 | 1995 | 49.192497966721 | 1994 | 49.226991218355 | 1993 | 49.259840990369 | 1992 | 49.291462504811 | 1991 | 49.345854296728 | 1990 | 49.409126487868 | 1989 | 49.454979531428 | 1988 | 49.499390541778 | 1987 | 49.54475573715 | 1986 | 49.59105274493 | 1985 | 49.637442320369 | 1984 | 49.683955756454 | 1983 | 49.729735617442 | 1982 | 49.776137582286 | 1981 | 49.827423909633 | 1980 | 49.868974686205 | 1979 | 49.884835154107 | 1978 | 49.879914003947 | 1977 | 49.857922218104 | 1976 | 49.821871492045 | 1975 | 49.771805361966 |
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