Year	Number
1971	2211
1972	2414
1973	2225
1974	2339
1975	2412
1976	2664
1977	2746
1978	2866
1979	3088
1980	3466
1981	3441
1982	3526
1983	3781
1984	3802
1985	3837
1986	4008
1987	4083
1988	4229
1989	4289
1992	4782
1995	4709
1996	4943
1997	4605
1999	5107
2001	5399
2002	6612
2003	7764
2011	12961
2019	10060