Year	Number
1996	32.5
1998	27.3631839752197
2000	30.348258972168
2002	18.4079608917236
2003	23.8805961608887
2004	25
2005	24.519229888916
2006	23.0769233703613
2007	24.519229888916
2008	21.634614944458
2009	20.8530807495117
2010	19.4312801361084
2011	20.1877937316895
2012	21.1267604827881
2013	19.2488269805908
2014	21.1822662353516
2015	21.674877166748
2016	22.660099029541
2017	22.660099029541
2018	21.8446598052979
2019	22.2222213745117
2020	21.7391300201416
2021	20.7729473114014
2022	21.7391300201416