Year	Overall average
2004	75.4901962745098
2005	74.7058825490196
2006	73.5947715686275
2007	75.0326798039216
2008	75.1633984313726
2009	76.7320258823529
2010	77.1895425490196
2011	77.2549019607843
2012	75.3594770588235
2013	74.8366013071895
2014	76.797385620915
2015	78.9542607843137
2016	78.4967392156863
2017	76.2091549019608
2018	75.8823588235294