Year	years
2003	3.1200000000000006
2004	3.074074074074074
2005	3.1034482758620685
2006	3.0999999999999996
2007	3.064516129032258
2008	3.064516129032258
2009	3.064516129032258
2010	3.064516129032258
2011	3.0548387096774183
2012	3.0548387096774188
2013	2.9903225806451608
2014	2.97741935483871
2015	2.9612903225806453
2016	2.94516129032258
2017	2.94516129032258
2018	2.9451612903225812
2019	2.9451612903225812