| Year | Value | | 2021 | 4.1282744238504 | | 2020 | 4.1282744238504 | | 2019 | 4.1282744238504 | | 2018 | 4.1282744238504 | | 2017 | 4.1282744238504 | | 2016 | 4.1282744238504 | | 2015 | 4.1282744238504 | | 2014 | 4.1282744238504 | | 2013 | 4.1282744238504 | | 2012 | 4.1282744238504 | | 2011 | 4.1282744238504 | | 2010 | 4.1282744238504 | | 2009 | 4.2346732492073 | | 2008 | 4.2346732492073 | | 2007 | 4.3410720745643 | | 2006 | 4.3410720745643 | | 2005 | 4.3410720745643 | | 2004 | 4.3410720745643 | | 2003 | 4.3410720745643 | | 2002 | 4.3410720745643 | | 2001 | 4.3410720745643 | | 2000 | 4.1282744238504 | | 1999 | 3.894197008065 | | 1998 | 3.7026791224225 | | 1997 | 3.7026791224225 | | 1996 | 3.7026791224225 | | 1995 | 3.7026791224225 | | 1994 | 3.5962802970655 | | 1993 | 3.374970740323 | | 1992 | 3.1643010661162 |
|