Year Number 1996 18.0904521942139 1998 12.5 2000 10.4477615356445 2002 5.47263669967651 2003 7.46268653869629 2004 8.65384578704834 2005 9.56937789916992 2006 9.56937789916992 2007 9.09090900421143 2008 9.61538505554199 2009 13.7440757751465 2010 13.2701425552368 2011 15.023473739624 2012 14.5539903640747 2013 15.023473739624 2014 18.269229888916 2015 17.619047164917 2016 16.6666660308838 2017 16.6666660308838 2018 19.0476188659668 2019 21.9047622680664 2020 26.1904754638672 2021 21.4285717010498 2022 20.2830181121826