Year	Number
1961	445900
1962	463552
1963	493607
1964	524754
1965	575735
1966	649889
1967	724402
1968	835590
1969	949800
1970	900036
1971	933556
1972	991802
1973	1090609
1974	1346986
1975	1252631
1976	1418230
1977	1616235
1978	1862904
1979	1983618
1980	2451579
1981	2458518
1982	2606773
1983	2693683
1984	2794057
1985	2942128
1986	2951143
1987	2963975
1988	3054030
1989	3115657
1990	3202110
1991	3032008
1992	3076394
1993	3123592
1994	3199361
1995	3293013
1996	3307891
1997	3386387