Year	Number
1961	172443
1962	185556
1963	198841
1964	211160
1965	222858
1966	242081
1967	276746
1968	298066
1969	325645
1970	349142
1971	404291
1972	436682
1973	465980
1974	501080
1975	541081
1976	589054
1977	659902
1978	735684
1979	815040
1980	841553
1981	906832
1982	975254
1983	1042701
1984	1153694
1985	1253124
1986	1349650
1987	1440845
1988	1539029
1989	1743521
1990	1862882
1991	1975933
1992	2644588
1993	2725612
1994	2807277
1995	2947307
1996	3092086
1997	3293686
1998	3352518
1999	3515953.5
2000	3581452
2001	3681352
2002	3835704