Year Number 1996 57.6086959838867 1998 54.8913040161133 2000 57.6086959838867 2002 57.2972984313965 2003 49.7297286987305 2004 58.2089538574219 2005 51.470588684082 2006 55.3921585083008 2007 61.6504859924316 2008 65.0485458374023 2009 68.4210510253906 2010 66.9856491088867 2011 69.1943130493164 2012 68.2464447021484 2013 67.7725143432617 2014 70.6730804443359 2015 67.1428604125977 2016 68.0952377319336 2017 70.9523773193359 2018 71.9047622680664 2019 72.3809509277344 2020 71.9047622680664 2021 70.476188659668 2022 68.8679275512695