Year	Number
1996	19.0217399597168
1998	16.8478260040283
2000	15.7608699798584
2002	14.0540542602539
2003	14.0540542602539
2004	6.46766185760498
2005	10.7843141555786
2006	20.5882358551025
2007	20.3883495330811
2008	22.3300971984863
2009	19.6172256469727
2010	17.2248802185059
2011	13.7440757751465
2012	19.9052124023438
2013	19.4312801361084
2014	12.9807691574097
2015	10
2016	8.09523773193359
2017	7.61904764175415
2018	8.5714282989502
2019	8.09523773193359
2020	10.4761905670166
2021	7.61904764175415
2022	8.49056625366211