Year	years
2003	2.29
2004	2.2
2005	2.423809523809524
2006	2.4521739130434788
2007	2.4760000000000004
2008	2.438461538461539
2009	2.438461538461539
2010	2.438461538461539
2011	2.435714285714286
2012	2.4103448275862065
2013	2.4103448275862065
2014	2.4103448275862065
2015	2.4103448275862065
2016	2.4103448275862065
2017	2.4103448275862065
2018	2.4103448275862065
2019	2.382758620689655