Year	Number
1971	304240
1972	315572
1973	353114
1974	388624
1975	457763
1976	493384
1977	552042
1978	664297
1979	781766
1980	897001
1981	954536
1982	1028348
1983	974250
1984	962003
1985	997071
1986	1038627
1987	1012426
1988	985123
1989	981409
1991	1023710
1993	992617
1996	1037482
1999	1038303
2000	1148545
2001	1178822
2003	1360751
2004	1571288
2007	1966640