Year	Overall average
2004	66.5432098148148
2005	68.2716048148148
2006	67.8078078378378
2007	68.048048018018
2008	67.6576575675676
2009	67.3684212280702
2010	68.245614122807
2011	68.421052368421
2012	67.3684209649123
2013	67.6900584795322
2014	69.3567251461988
2015	70.3508885964912
2016	69.7368456140351
2017	69.4444456140351
2018	72.0760298245614