| Year | Value | | 2022 | 2.5226236653861 | | 2021 | 1.9669245168038 | | 2020 | 2.0695371860456 | | 2019 | 1.9976190565754 | | 2018 | 1.9663749466677 | | 2017 | 1.712070467612 | | 2016 | 1.477505871857 | | 2015 | 1.137748173579 | | 2014 | 0.87959625774436 | | 2013 | 0.76290748208421 | | 2012 | 0.76526581014274 | | 2011 | 0.79070084805226 | | 2010 | 0.87865909205057 | | 2009 | 1.0828037827999 | | 2008 | 1.1316085519121 | | 2007 | 1.1136075672726 | | 2006 | 1.1651848132255 | | 2005 | 1.1634540076135 | | 2004 | 1.1959432818628 | | 2003 | 1.1212284980651 | | 2002 | 1.2712887463159 | | 2001 | 1.3619436375338 | | 2000 | 1.2166999904796 | | 1999 | 0.97010249182819 | | 1998 | 1.2292543361905 | | 1997 | 0.74711115285445 | | 1996 | 0.50398000923095 | | 1995 | 0.45437287379461 | | 1994 | 0.49337759849243 | | 1993 | 0.81226064332592 |
|