Year | Value | 2021 | 19.6875 | 2020 | 19.82421875 | 2019 | 19.82421875 | 2018 | 20.09765625 | 2017 | 20.703125 | 2016 | 20.0390625 | 2015 | 19.9609375 | 2014 | 19.6484375 | 2013 | 19.70703125 | 2012 | 19.58984375 | 2011 | 19.62890625 | 2010 | 19.609375 | 2009 | 19.47265625 | 2008 | 19.6875 | 2007 | 19.9609375 | 2006 | 20.05859375 | 2005 | 20.01953125 | 2004 | 20.078125 | 2003 | 19.86328125 | 2002 | 19.47265625 | 2001 | 19.7265625 | 2000 | 19.53125 | 1999 | 18.5546875 | 1998 | 18.5546875 | 1997 | 17.578125 | 1996 | 17.578125 | 1995 | 16.6015625 | 1994 | 16.6015625 | 1993 | 16.6015625 | 1992 | 16.6015625 |
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