Year	Number
1961	52661
1962	55360
1963	59657
1964	66290
1965	73021
1966	100432
1967	125442
1968	155602
1969	180772
1970	126440
1971	151281
1972	191220
1973	235524
1974	282282
1975	346786
1976	398946
1977	469106
1978	559638
1979	669675
1980	747900
1981	796867
1982	817857
1983	847916
1984	862078
1985	861364
1986	876470
1987	891170
1988	880859
1989	858031
1990	824113
1991	795713
1992	770629
1993	734325
1994	705723
1995	685202
1996	684290
1997	703117
1998	738526
1999	798506
2000	989139