Year	number
2005	48.4
2006	47.19047619047619
2007	46.95238095238095
2008	46.904761904761905
2009	46.857142857142854
2010	46.19047619047619
2011	46.285714285714285
2012	45.61904761904762
2013	45.18181818181818
2014	45.72727272727273
2015	45.40909090909091
2016	44.13636363636363
2017	43.54545454545455
2018	44.63636363636363
2019	42.90909090909091