Year	Number
1996	15.2173910140991
1998	13.5869569778442
2000	9.78260898590088
2002	12.4324321746826
2003	8.10810852050781
2004	7.96019887924194
2005	7.84313726425171
2006	8.82352924346924
2007	11.1650485992432
2008	13.1067962646484
2009	13.8755979537964
2010	17.7033500671387
2011	18.4834117889404
2012	23.222749710083
2013	22.748815536499
2014	20.1923084259033
2015	22.380952835083
2016	23.8095245361328
2017	24.2857151031494
2018	18.5714282989502
2019	22.380952835083
2020	19.5238094329834
2021	17.619047164917
2022	16.0377349853516