Year	Number
2005	9.51486345696468
2006	9.70024383905477
2007	8.391722923161588
2008	7.03102285574656
2009	7.439045916570195
2010	5.699942464637819
2011	4.1459567192228235
2012	4.853797520112086
2013	4.348701380826959
2014	3.075031893212361
2015	2.094650527670993
2016	1.2190963653969418