Year	Number
1996	22.4043712615967
1998	27.8688526153564
2000	32.7868843078613
2002	29.7297306060791
2003	27.027027130127
2004	26.3681583404541
2005	31.3725490570068
2006	30.7317066192627
2007	33.4951438903809
2008	31.5533981323242
2009	29.1866035461426
2010	31.1004791259766
2011	37.4407577514648
2012	28.9099521636963
2013	27.962085723877
2014	20.6730766296387
2015	19.5238094329834
2016	22.8571434020996
2017	31.9047622680664
2018	30.9523811340332
2019	30.4761905670166
2020	28.5714282989502
2021	20
2022	19.3396224975586