Year	Number
1996	14.8936166763306
1998	29.2553195953369
2000	25.9259262084961
2002	23.8095245361328
2003	21.608039855957
2004	19.4174766540527
2005	16.990291595459
2006	15.9420289993286
2007	18.3574886322021
2008	15.865385055542
2009	21.8009471893311
2010	19.4312801361084
2011	20.3791465759277
2012	21.8009471893311
2013	19.9052124023438
2014	17.1428565979004
2015	20.9523811340332
2016	20
2017	16.1904754638672
2018	16.5094337463379
2019	14.6226415634155
2020	18.3962268829346
2021	15.0943393707275
2022	15.0943393707275