| Year | Value | | 2022 | 63.103314523109 | | 2021 | 62.015663810714 | | 2020 | 62.529490119328 | | 2019 | 62.967468117187 | | 2018 | 62.942876031822 | | 2017 | 63.379127530606 | | 2016 | 63.776927811694 | | 2015 | 64.145793687807 | | 2014 | 64.535997820804 | | 2013 | 64.209110887019 | | 2012 | 64.064594579749 | | 2011 | 63.049231441645 | | 2010 | 62.866085920775 | | 2009 | 62.694569524873 | | 2008 | 62.936393706165 | | 2007 | 62.773954000721 | | 2006 | 61.674898533837 | | 2005 | 61.029368552052 | | 2004 | 60.500029735167 | | 2003 | 59.926120631032 | | 2002 | 59.852162433627 | | 2001 | 60.083164938061 | | 2000 | 60.318359975921 | | 1999 | 59.85868541105 | | 1998 | 60.088748730943 | | 1997 | 59.797166711941 | | 1996 | 60.005128553431 | | 1995 | 59.365619492445 | | 1994 | 59.012562390254 | | 1993 | 58.81969225286 | | 1992 | 59.036464041526 | | 1991 | 59.218019606736 |
|