Year	Number
1996	43.5
1998	36.8159217834473
2000	37.8109436035156
2002	36.3184089660645
2003	32.3383102416992
2004	30.769229888916
2005	27.4038467407227
2006	22.115385055542
2007	22.5961532592773
2008	22.5961532592773
2009	23.222749710083
2010	23.6966819763184
2011	24.4131450653076
2012	19.2488269805908
2013	18.7793426513672
2014	20.6896553039551
2015	20.1970443725586
2016	17.7339897155762
2017	18.7192115783691
2018	18.9320392608643
2019	17.8743953704834
2020	20.2898559570313
2021	19.8067626953125
2022	14.4927539825439