| Year | Value | | 2022 | 72.578049310356 | | 2021 | 72.580621999098 | | 2020 | 72.644499133918 | | 2019 | 71.099929451147 | | 2018 | 68.736564408064 | | 2017 | 69.288795347149 | | 2016 | 69.830368134921 | | 2015 | 62.580259427028 | | 2014 | 60.829431660592 | | 2013 | 61.122572427559 | | 2012 | 62.488865893463 | | 2011 | 61.17371775907 | | 2010 | 62.204855151117 | | 2009 | 60.585725614361 | | 2008 | 60.013855583301 | | 2007 | 58.530731866949 | | 2006 | 61.804787748613 | | 2005 | 60.000101800171 | | 2004 | 56.486478792176 | | 2003 | 57.872575592322 | | 2002 | 60.188054410784 | | 2001 | 61.503369165444 | | 2000 | 59.941760556851 | | 1999 | 61.11903543207 | | 1998 | 59.760003227815 | | 1997 | 59.965760622188 | | 1996 | 58.522115673165 | | 1995 | 57.123698340441 | | 1994 | 56.390947715112 | | 1993 | 55.769115901186 | | 1992 | 55.619773418083 | | 1991 | 55.46410949489 |
|