| Year | Value | | 2022 | 48.77414795929 | | 2021 | 48.385077158407 | | 2020 | 48.077415987436 | | 2019 | 48.227440980789 | | 2018 | 47.761592114128 | | 2017 | 47.314954093453 | | 2016 | 46.872566793756 | | 2015 | 46.181183247688 | | 2014 | 45.534860558284 | | 2013 | 45.254669021245 | | 2012 | 45.061264957416 | | 2011 | 44.908595837833 | | 2010 | 44.682572720585 | | 2009 | 44.487173189428 | | 2008 | 44.305420782617 | | 2007 | 44.14353766159 | | 2006 | 44.022407797019 | | 2005 | 43.93147597315 | | 2004 | 43.843496964664 | | 2003 | 43.809870465622 | | 2002 | 43.852748686408 | | 2001 | 43.942231637472 | | 2000 | 44.095888009655 | | 1999 | 44.226470333436 | | 1998 | 44.444875622478 | | 1997 | 44.744367264906 | | 1996 | 45.127219646959 | | 1995 | 45.425833632161 | | 1994 | 45.784125048113 | | 1993 | 46.161412926621 | | 1992 | 46.105120423581 | | 1991 | 46.038627527357 |
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