Year	Number
1996	29.1457290649414
1998	24
2000	21.3930339813232
2002	13.9303483963013
2003	16.9154224395752
2004	17.7884616851807
2005	19.1387557983398
2006	19.1387557983398
2007	18.1818180084229
2008	20.6730766296387
2009	21.8009471893311
2010	24.6445503234863
2011	25.3521118164063
2012	25.3521118164063
2013	25.8215961456299
2014	32.6923065185547
2015	30
2016	26.1904754638672
2017	28.0952377319336
2018	30
2019	30.4761905670166
2020	37.1428565979004
2021	31.4285717010498
2022	30.1886787414551