Year Number 1996 43.5483856201172 1998 44.9197845458984 2000 45.2127647399902 2002 48.6772499084473 2003 51.8518524169922 2004 34.9753684997559 2005 28.7804870605469 2006 26.8292675018311 2007 28.1553401947021 2008 27.6699028015137 2009 34.4497604370117 2010 32.8571434020996 2011 37.4407577514648 2012 30.8056869506836 2013 27.488151550293 2014 28.365385055542 2015 23.3333339691162 2016 20 2017 29.5238094329834 2018 37.1428565979004 2019 39.523811340332 2020 38.0952377319336 2021 40.9523811340332 2022 46.2264137268066