Year	Number
1996	3.01507544517517
1998	5
2000	6.46766185760498
2002	15.9203977584839
2003	16.4179096221924
2004	12.9807691574097
2005	14.3540668487549
2006	10.5263156890869
2007	8.13397121429443
2008	8.17307662963867
2009	8.05687236785889
2010	9.95260620117188
2011	9.85915470123291
2012	9.38967132568359
2013	8.45070457458496
2014	13.4615383148193
2015	12.380952835083
2016	10.4761905670166
2017	7.61904764175415
2018	7.61904764175415
2019	8.5714282989502
2020	9.0476188659668
2021	10.4761905670166
2022	10.8490562438965