Year	Number
1971	13276
1972	14741
1974	16182
1975	18437
1976	21454
1977	21967
1978	24255
1979	29209
1980	32687
1981	33514
1982	35825
1983	38678
1984	42374
1985	40715
1986	42998
1987	48459
1988	50054
1989	53937
1993	59117
1996	62296
1999	56130
2000	62034
2003	84090
2004	90825
2007	148363