Year	Number
1996	9.04522609710693
1998	6
2000	8.4577112197876
2002	8.4577112197876
2003	6.46766185760498
2004	6.73076915740967
2005	8.13397121429443
2006	8.61244010925293
2007	8.61244010925293
2008	8.65384578704834
2009	4.26540279388428
2010	4.7393364906311
2011	5.16431903839111
2012	3.75586843490601
2013	6.57277011871338
2014	7.21153831481934
2015	5.2380952835083
2016	8.09523773193359
2017	6.1904764175415
2018	5.2380952835083
2019	5.2380952835083
2020	4.7619047164917
2021	5.2380952835083
2022	6.60377359390259