Year | Value | 2022 | 19.583710946013 | 2021 | 20.471551437906 | 2020 | 21.159510935813 | 2019 | 20.255840336125 | 2018 | 19.518309144204 | 2017 | 18.886346404785 | 2016 | 19.249536575825 | 2015 | 19.71678498013 | 2014 | 18.089313424464 | 2013 | 17.394170034525 | 2012 | 16.931510796601 | 2011 | 17.53765051463 | 2010 | 15.89172294697 | 2009 | 16.673938249522 | 2008 | 17.958376506782 | 2007 | 18.567864822805 | 2006 | 17.106708945785 | 2005 | 16.518816440491 | 2004 | 14.10288373417 | 2003 | 16.234278529709 | 2002 | 15.518120311026 | 2001 | 17.22849800652 | 2000 | 18.424617379419 | 1999 | 20.201499875765 | 1998 | 21.285388772581 | 1997 | 20.361849282983 | 1996 | 20.645939517987 | 1995 | 21.092022753724 |
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