| Year | Value | | 2022 | 66.908672436956 | | 2021 | 66.476825863777 | | 2020 | 65.841183043857 | | 2019 | 65.573008216092 | | 2018 | 64.616985417005 | | 2017 | 62.866191352716 | | 2016 | 60.858660383464 | | 2015 | 58.767042967226 | | 2014 | 55.91306761157 | | 2013 | 55.236015066191 | | 2012 | 61.562984459485 | | 2011 | 61.515376029743 | | 2010 | 61.427363793259 | | 2009 | 59.390781581747 | | 2008 | 56.779058059309 | | 2007 | 54.001095505474 | | 2006 | 51.617376275204 | | 2005 | 50.190179138037 | | 2004 | 49.116118649668 | | 2003 | 47.658515901769 | | 2002 | 46.90640995491 | | 2001 | 46.529983569756 | | 2000 | 46.174778211638 | | 1999 | 45.655543270365 | | 1998 | 45.281330081186 | | 1997 | 45.194701452784 | | 1996 | 45.00043077698 | | 1995 | 45.188521594692 | | 1994 | 45.612253246966 | | 1993 | 46.036096024545 | | 1992 | 46.405111778078 | | 1991 | 46.449330221674 |
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