Year	Number
1960	0
1965	0
1970	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	0
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	0
1990	0
1991	0
1992	0
1993	1150
1994	2559
1995	3005
1996	5400
1997	7200
1998	11474
1999	13080
2000	13927
2001	14302
2002	14874
2003	15081
2004	15750
2005	17191
2006	18307
2007	20400
2008	22000
2009	23000
2010	23414
2011	31789
2012	33195
2013	35464
2014	33675
2015	34020
2016	33297
2017	32978
2018	32689
2019	33783
2020	35485
2021	37426
2022	38955