Year	Number
1970	1167
1971	1167
1972	1167
1973	1167
1974	1167
1975	1551
1976	1635
1977	1660
1978	1920
1979	2270
1980	2624
1981	2990
1982	3420
1983	3624
1984	3670
1985	4048
1986	4299
1987	4452
1988	4801
1989	4806
1990	5710
1991	6230
1992	6789
1993	7349
1994	7516
1995	7556
1996	8151
1997	8283
1998	7932
1999	8831
2000	9704
2001	9932
2002	10125
2003	10169
2004	11103
2005	10578
2006	11301
2007	14113
2008	14910
2009	16842
2010	18474
2011	18442
2012	19955
2013	20686
2014	21912
2015	22902
2016	24925
2017	36582
2018	36855
2019	37107
2020	38866
2021	27326
2022	27931