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	700
1993	900
1994	1200
1995	1250
1996	1300
1997	1400
1998	1500
1999	1800
2000	1992
2001	2156
2002	2036
2003	2100
2004	2250