Year	Number
1960	0
1961	0
1962	0
1963	0
1964	0
1965	100
1966	100
1967	100
1968	100
1969	100
1970	300
1971	300
1972	300
1973	300
1974	300
1975	450
1976	500
1977	600
1978	700
1979	800
1980	900
1981	1000
1982	1100
1983	1200
1984	1400
1985	1594
1986	1772
1987	2013
1988	2314
1989	2889
1990	3265
1991	3641
1992	3851
1993	4010
1994	4272
1995	4377
1996	4980
1997	5507
1998	6226
1999	6521
2000	6773
2001	8876
2002	10258
2003	13245
2004	15083
2005	16939
2006	19061
2007	26025
2008	28809
2009	30787
2010	21210
2011	23146
2012	24000
2013	23000
2014	23500
2015	14599
2016	13049
2017	17212
2018	10320
2019	10042
2020	7573
2021	7407
2022	7370