Year	Number
1961	45500
1962	48100
1963	51500
1964	54900
1965	60167
1966	64200
1967	66400
1968	72000
1969	77700
1970	84349
1971	89900
1972	94000
1973	98300
1974	106000
1975	114217
1976	120000
1977	125000
1978	130000
1979	135000
1980	145100
1981	148000
1982	150000
1983	152000
1984	155000
1985	158000
1986	160500
1987	163000
1988	165000
1989	167000
1990	169000
1991	171000
1992	172000
1993	173000
1994	174500
1995	176500
1996	178000
1997	179557
1998	174414
1999	169123
2000	159525
2001	160920
2002	162310
2003	163700
2004	169250
2005	174800