Year scale 0 - 100 2004 66.7948717948718 2005 67.94871794871794 2006 67.56410256410257 2007 68.10126582278481 2008 68.86075949367088 2009 68.14814814814815 2010 67.28395061728395 2011 68.0246913580247 2012 66.41975308641975 2013 66.34146341463415 2014 66.58536585365853 2015 68.43373493975903 2016 69.27710843373494 2017 67.95180722891567 2018 62.16867469879518 2019 63.13253012048193 2020 60.36144578313253