Year	Number
1996	25.8064517974854
1998	28.3422451019287
2000	18.6170215606689
2002	6.34920644760132
2003	8.99470901489258
2004	11.822660446167
2005	18.0487804412842
2006	20
2007	21.8446598052979
2008	31.0679607391357
2009	22.4880390167236
2010	21.4285717010498
2011	18.4834117889404
2012	18.0094795227051
2013	15.6398105621338
2014	13.4615383148193
2015	20
2016	22.380952835083
2017	18.0952377319336
2018	18.0952377319336
2019	19.5238094329834
2020	20
2021	20.9523811340332
2022	21.2264156341553