Year	number
2005	58.8421052631579
2006	59.85
2007	58.2
2008	56.75
2009	55.19047619047619
2010	50.904761904761905
2011	44.95238095238095
2012	33.523809523809526
2013	30.727272727272727
2014	24.181818181818183
2015	21.454545454545453
2016	17.863636363636363
2017	15.409090909090908
2018	15.5
2019	13.863636363636363