| Year | Value | | 2022 | 58.567650523861 | | 2021 | 58.017098982123 | | 2020 | 57.942026521109 | | 2019 | 58.317155768365 | | 2018 | 57.956206059146 | | 2017 | 57.594813732105 | | 2016 | 57.376829188228 | | 2015 | 57.147721634221 | | 2014 | 56.717483655514 | | 2013 | 55.999434025343 | | 2012 | 55.40717833941 | | 2011 | 54.473472220184 | | 2010 | 53.697314947242 | | 2009 | 52.978944861677 | | 2008 | 52.504559892595 | | 2007 | 51.677693549207 | | 2006 | 50.85061588818 | | 2005 | 50.038918420153 | | 2004 | 49.09034636931 | | 2003 | 48.083559767138 | | 2002 | 47.629129842882 | | 2001 | 47.016664368787 | | 2000 | 46.252173731088 | | 1999 | 45.691314537407 | | 1998 | 45.079440344249 | | 1997 | 44.878607362293 | | 1996 | 44.525623797525 | | 1995 | 43.920774478591 | | 1994 | 43.433263810264 | | 1993 | 43.117376139195 | | 1992 | 42.773314106035 | | 1991 | 42.522513331476 |
|