Year	Number
1970	3710
1971	4199
1972	4644
1973	4140
1974	5048
1975	4623
1976	4832
1977	5383
1978	5648
1979	5578
1980	6248
1981	5790
1982	5557
1985	9241
1986	9112
1987	7532
1988	8950
1989	8218
1990	7982
1994	9486