Year	Number
1961	320
1962	340
1963	360
1964	380
1965	400
1966	420
1967	440
1968	460
1969	480
1970	500
1971	520
1972	540
1973	560
1974	580
1975	603
1976	700
1977	788
1978	826
1979	926
1980	990
1981	1050
1982	1110
1983	1175
1984	1239
1985	1260
1986	1270
1987	1280
1988	1300
1989	1320
1990	1330
1991	1635
1992	1660
1993	1685
1994	1710
1995	1735
1996	1761
1997	1787
1998	1813
1999	1839
2000	1865
2002	1941