Year	Number
1996	14.5
1998	10.4477615356445
2000	7.46268653869629
2002	6.96517419815063
2003	7.96019887924194
2004	6.73076915740967
2005	5.28846168518066
2006	2.88461542129517
2007	2.4038462638855
2008	3.36538457870483
2009	2.84360194206238
2010	2.84360194206238
2011	2.3474178314209
2012	3.28638505935669
2013	3.75586843490601
2014	4.43349742889404
2015	4.43349742889404
2016	5.9113302230835
2017	5.9113302230835
2018	10.6796112060547
2019	7.72946882247925
2020	13.043478012085
2021	16.9082126617432
2022	18.3574886322021