Year | Value | 2022 | 21.386717789401 | 2021 | 22.347601663037 | 2020 | 22.690317672044 | 2019 | 22.580881011896 | 2018 | 22.237309349894 | 2017 | 22.112083789403 | 2016 | 22.053622270436 | 2015 | 22.76575288205 | 2014 | 21.888678671986 | 2013 | 21.232398115507 | 2012 | 20.095907523385 | 2011 | 20.206214914242 | 2010 | 19.348346619855 | 2009 | 19.528662416152 | 2008 | 20.517238118883 | 2007 | 20.228135370631 | 2006 | 19.486313090734 | 2005 | 18.88878528243 | 2004 | 17.811612867261 | 2003 | 18.391358057377 | 2002 | 19.198344646853 | 2001 | 19.915151716131 | 2000 | 20.006370595323 | 1999 | 19.639868217747 | 1998 | 21.11721870866 | 1997 | 20.889550318977 | 1996 | 20.624374138919 | 1995 | 21.694394298395 |
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