Year Number 1996 68.0851058959961 1998 73.4042587280273 2000 79.3650817871094 2002 75.1322784423828 2003 70.3517608642578 2004 64.5631103515625 2005 69.4174728393555 2006 75.3623199462891 2007 77.2946853637695 2008 75.961540222168 2009 73.459716796875 2010 74.8815155029297 2011 78.6729888916016 2012 69.6682434082031 2013 71.5639801025391 2014 83.8095245361328 2015 84.2857131958008 2016 88.5714263916016 2017 86.1904754638672 2018 85.8490600585938 2019 83.9622650146484 2020 86.7924499511719 2021 87.2641525268555 2022 88.2075500488281