Year scale 0 - 100 2004 68.97435897435898 2005 71.28205128205128 2006 70.76923076923077 2007 71.7948717948718 2008 73.84615384615384 2009 72.25 2010 71.25 2011 72.5 2012 70.75 2013 70.73170731707317 2014 70 2015 72.1951219512195 2016 72.6829268292683 2017 71.70731707317073 2018 62.926829268292686 2019 63.65853658536585 2020 61.707317073170735