Year scale 0 - 100 2004 75.83333300000001 2005 78.16666599999999 2006 77.66666599999999 2007 78.8333325 2008 78.33333299999998 2009 78.57142904761905 2010 81.1111119047619 2011 82.22222238095236 2012 81.58730047619048 2013 80.63492063492065 2014 79.52380952380953 2015 83.01590952380951 2016 82.22225714285713 2017 83.49209047619048 2018 84.60319999999999 2019 83.65081904761904 2020 82.06351428571428