Year Number 1996 20.218578338623 1998 21.3114757537842 2000 20.218578338623 2002 25.9459457397461 2003 28.6486492156982 2004 33.3333320617676 2005 24.0196075439453 2006 20 2007 18.4466018676758 2008 17.9611644744873 2009 19.6172256469727 2010 16.2679424285889 2011 15.6398105621338 2012 14.2180099487305 2013 17.5355453491211 2014 15.865385055542 2015 14.2857141494751 2016 13.8095235824585 2017 12.8571424484253 2018 15.2380952835083 2019 19.5238094329834 2020 21.4285717010498 2021 19.0476188659668 2022 22.1698112487793