Year Number 1996 27.6381912231445 1998 26 2000 26.3681583404541 2002 30.348258972168 2003 38.8059692382813 2004 40.8653831481934 2005 41.1483268737793 2006 40.1913871765137 2007 41.6267929077148 2008 42.3076934814453 2009 44.5497627258301 2010 42.6540298461914 2011 43.1924896240234 2012 40.3755874633789 2013 42.7230033874512 2014 33.6538467407227 2015 32.3809509277344 2016 28.5714282989502 2017 29.5238094329834 2018 28.0952377319336 2019 29.0476188659668 2020 32.3809509277344 2021 33.8095245361328 2022 36.7924537658691