Year	Number
2004	29937
2005	34971
2006	33090
2007	28538
2008	27264
2009	23415
2010	24070
2011	22612
2012	20942
2013	22744
2014	21169
2015	19950
2016	20575
2017	18583
2018	19182
2019	20262
2020	21143
2021	20988