Year	Number
1990	17016
1991	17463
1992	17806
1993	17963
1994	18350
1995	19696
1996	23238
1997	18798
1998	18395
1999	18568
2000	18842
2001	19211
2002	19681
2003	20199
2004	20645
2005	21247
2006	21900
2007	22631
2008	23421
2009	24132
2010	24806
2011	25467
2012	26204
2013	26883
2014	27660
2015	28574
2016	29646
2017	30514
2018	31186
2019	31699
2020	32098
2021	32533
2022	33117