Year	Number
1996	7.5
1998	8.4577112197876
2000	7.46268653869629
2002	14.4278602600098
2003	13.9303483963013
2004	12.0192308425903
2005	28.365385055542
2006	27.4038467407227
2007	26.9230766296387
2008	28.8461532592773
2009	29.3838863372803
2010	20.8530807495117
2011	21.1267604827881
2012	23.474178314209
2013	21.5962448120117
2014	21.1822662353516
2015	13.3004922866821
2016	7.88177347183228
2017	6.40394067764282
2018	5.82524251937866
2019	4.8309178352356
2020	6.7632851600647
2021	12.0772943496704
2022	10.6280193328857