| Year | Value | | 2021 | 34.248093250828 | | 2020 | 34.219312131242 | | 2019 | 34.14304216434 | | 2018 | 34.166067060009 | | 2017 | 34.318606993812 | | 2016 | 34.451000143906 | | 2015 | 34.797812634912 | | 2014 | 34.767592459347 | | 2013 | 35.77637070082 | | 2012 | 35.041013095409 | | 2011 | 35.147503237876 | | 2010 | 35.400777090229 | | 2009 | 35.947618362354 | | 2008 | 36.177867319039 | | 2007 | 36.221038998417 | | 2006 | 36.23542955821 | | 2005 | 36.264210677795 | | 2004 | 35.861275003598 | | 2003 | 43.258022737085 | | 2002 | 43.229241617499 | | 2001 | 43.214851057706 | | 2000 | 43.171679378328 | | 1999 | 43.157288818535 | | 1998 | 43.819254569003 | | 1997 | 43.70413009066 | | 1996 | 43.675348971075 | | 1995 | 43.862426248381 | | 1994 | 44.567563678227 | | 1993 | 45.013671031803 | | 1992 | 46.467117570873 |
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