| Year | Value | | 2021 | 71.74940641 | | 2020 | 70.78874796 | | 2019 | 68.68550299 | | 2018 | 59.6 | | 2017 | 50.32012015 | | 2016 | 48.05227375 | | 2015 | 45.78453653 | | 2014 | 38.07120929 | | 2013 | 30.53803344 | | 2012 | 24 | | 2011 | 18 | | 2010 | 13 | | 2009 | 9.5 | | 2008 | 7.5 | | 2007 | 5.767004576 | | 2006 | 5.489200803 | | 2005 | 4.89326475 | | 2004 | 2.9790698 | | 2003 | 2.659586594 | | 2002 | 1.939530106 | | 2001 | 1.347620222 | | 2000 | 1.216140618 | | 1999 | 0.249009564 | | 1998 | 0.17012488 | | 1997 | 0.047999009 |
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