Year	Number
1996	8
1998	9.95024871826172
2000	12.93532371521
2002	12.93532371521
2003	10.4477615356445
2004	10.5769233703613
2005	8.65384578704834
2006	8.17307662963867
2007	8.65384578704834
2008	7.692307472229
2009	8.05687236785889
2010	7.10900497436523
2011	7.0422534942627
2012	6.57277011871338
2013	5.16431903839111
2014	4.43349742889404
2015	3.94088673591614
2016	3.94088673591614
2017	3.94088673591614
2018	4.36893224716187
2019	4.34782600402832
2020	4.34782600402832
2021	1.93236720561981
2022	4.8309178352356