| Year | Value | | 2021 | 1.07 | | 2020 | 1.03 | | 2019 | 1.04 | | 2018 | 1.05 | | 2017 | 1.04 | | 2016 | 5.99 | | 2015 | 1.17 | | 2013 | 5.99 | | 2012 | 2.71 | | 2011 | 2.71 | | 2010 | 2.75 | | 2009 | 2.77 | | 2008 | 2.8 | | 2007 | 2.99 | | 2006 | 2.27 | | 2005 | 4.86 | | 2004 | 4.88 | | 2003 | 5.9 | | 2002 | 6.99 | | 2001 | 8 | | 2000 | 9 | | 1999 | 9.99 | | 1998 | 10.99 | | 1997 | 10.99 | | 1996 | 10.99 | | 1995 | 10.67 | | 1994 | 10.99 | | 1993 | 10.99 | | 1992 | 10.99 |
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