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	171
1993	438
1994	964
1995	2052
1996	4122
1997	6481
1998	8899
1999	13521
2000	15114
2001	15882
2002	19924
2003	29749
2004	39033
2005	46480
2006	53900
2007	66400
2008	55816
2009	53468
2010	57349
2011	58742
2012	59455
2013	60400
2014	60800
2015	61000
2017	62320
2018	61394
2019	61656
2020	65958
2021	66605