| Year | Value | | 2022 | 84.993615397366 | | 2021 | 85.063022899534 | | 2020 | 85.052509628083 | | 2019 | 84.942662893728 | | 2018 | 85.158253585908 | | 2017 | 84.844649917561 | | 2016 | 84.55929623755 | | 2015 | 84.84273382582 | | 2014 | 84.871965722749 | | 2013 | 84.425884310564 | | 2012 | 84.523743154518 | | 2011 | 84.058646158381 | | 2010 | 84.023013537937 | | 2009 | 84.629172299274 | | 2008 | 85.686039510185 | | 2007 | 86.070783358305 | | 2006 | 86.691447198094 | | 2005 | 87.139633982217 | | 2004 | 87.594590866577 | | 2003 | 88.301227583535 | | 2002 | 88.903939491272 | | 2001 | 89.253244406525 | | 2000 | 89.715379289911 | | 1999 | 90.029132233639 | | 1998 | 90.956929930102 | | 1997 | 93.680591287802 | | 1996 | 93.599725695468 | | 1995 | 93.474019432438 | | 1994 | 93.697292834329 | | 1993 | 93.902115851795 | | 1992 | 94.017895008043 | | 1991 | 94.328163357362 |
|