Year	Number
1996	14.5
1998	12.4378108978271
2000	14.4278602600098
2002	18.9054718017578
2003	18.9054718017578
2004	23.5576915740967
2005	25.480770111084
2006	22.5961532592773
2007	20.1923084259033
2008	20.6730766296387
2009	17.5355453491211
2010	18.4834117889404
2011	20.1877937316895
2012	22.5352115631104
2013	23.9436626434326
2014	25.1231517791748
2015	24.630542755127
2016	23.645320892334
2017	23.1527099609375
2018	21.3592224121094
2019	19.8067626953125
2020	19.3236713409424
2021	20.7729473114014
2022	21.7391300201416