Year	years
2003	2.604761904761905
2004	2.604761904761905
2005	2.604761904761905
2006	2.6454545454545455
2007	2.645454545454545
2008	2.645454545454545
2009	2.645454545454545
2010	2.645454545454545
2011	2.5545454545454542
2012	2.660869565217391
2013	2.3692307692307693
2014	2.338461538461538
2015	2.338461538461538
2016	2.338461538461538
2017	2.338461538461538
2018	2.338461538461538
2019	2.338461538461538