Year	Number
1971	512
1972	668
1976	1016
1977	1121
1978	1317
1979	1383
1980	1437
1981	1587
1982	1583
1983	1743
1984	2135
1985	2210
1986	2074
1987	2120
1988	2271
1989	2091
1995	2382
1996	3094
1997	2692
1999	3078
2019	9976