| Year | Value | | 2021 | 61.849361129791 | | 2020 | 61.943510423672 | | 2019 | 62.037659717552 | | 2018 | 62.131809011432 | | 2017 | 62.246133154001 | | 2016 | 62.320107599193 | | 2015 | 62.414256893073 | | 2014 | 62.508406186954 | | 2013 | 62.602555480834 | | 2012 | 62.696704774714 | | 2011 | 62.790854068594 | | 2010 | 62.885003362475 | | 2009 | 62.979152656355 | | 2008 | 63.073301950235 | | 2007 | 63.167451244116 | | 2006 | 63.261600537996 | | 2005 | 63.355749831876 | | 2004 | 63.449899125757 | | 2003 | 63.544048419637 | | 2002 | 63.638197713517 | | 2001 | 63.732347007398 | | 2000 | 63.826496301278 | | 1999 | 63.920645595158 | | 1998 | 64.014794889038 | | 1997 | 64.108944182919 | | 1996 | 64.203093476799 | | 1995 | 64.297242770679 | | 1994 | 64.391392064559 | | 1993 | 64.48554135844 | | 1992 | 64.57969065232 | | 1991 | 64.6738399462 | | 1990 | 64.767989240081 |
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