| Year | Value | | 2021 | 32.069395776456 | | 2020 | 32.17877335229 | | 2019 | 32.179987177079 | | 2018 | 32.171998445797 | | 2017 | 32.327418728144 | | 2016 | 32.262660277166 | | 2015 | 32.249708586971 | | 2014 | 32.232582232582 | | 2013 | 32.387982387982 | | 2012 | 32.614269066425 | | 2011 | 32.650653890975 | | 2010 | 32.991454098148 | | 2009 | 33.426721905748 | | 2008 | 33.664422578975 | | 2007 | 33.99715210356 | | 2006 | 34.141618122977 | | 2005 | 35.107688325136 | | 2004 | 35.34157390629 | | 2003 | 35.709589750226 | | 2002 | 35.973728484535 | | 2001 | 41.879125145593 | | 2000 | 41.969716578232 | | 1999 | 42.137957810276 | | 1998 | 42.202665976446 | | 1997 | 42.060308010871 | | 1996 | 42.15089944351 | | 1995 | 42.720331305811 | | 1994 | 42.927397437557 | | 1993 | 43.121521936068 |
|