Year | Value | 2022 | 31.356719413056 | 2021 | 31.32293998304 | 2020 | 30.597205343054 | 2019 | 30.563108913959 | 2018 | 31.503045192616 | 2017 | 33.952696432144 | 2016 | 36.72227973652 | 2015 | 30.683098280193 | 2014 | 30.841882120368 | 2013 | 30.882273654679 | 2012 | 30.363724646305 | 2011 | 29.94760163035 | 2010 | 29.659268796998 | 2009 | 29.60974395862 | 2008 | 29.587314608299 | 2007 | 29.932529198866 | 2006 | 29.902300345154 | 2005 | 30.864006142938 | 2004 | 29.535523366336 | 2003 | 30.220314951112 | 2002 | 30.191255117201 | 2001 | 28.587392751562 | 2000 | 28.457149203944 | 1999 | 28.166615861942 | 1998 | 28.070092309883 | 1997 | 28.512557334995 | 1996 | 27.620660870075 | 1995 | 27.60024788335 | 1994 | 27.678043282573 | 1993 | 27.733474150901 | 1992 | 27.805873312899 | 1991 | 27.846052454473 |
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