Year	Number
1971	2824
1972	2788
1985	4494
1986	4779
1989	6215
1990	7327
1991	7980
1992	9126
1994	8905
1995	8826
1996	9395
1997	10151
1998	11641
1999	12373
2000	13313
2001	13819
2002	15971
2003	16142
2004	18510
2005	19989
2006	20670
2007	21933
2008	24514
2009	27388
2010	27764
2011	30813
2012	34125
2013	37336
2014	43490
2015	40872
2016	38905
2017	39611
2018	43805
2019	44691
2021	48394
2022	49875