Year	Number
1961	54800
1962	59200
1963	62800
1964	68749
1965	72000
1966	75100
1967	79200
1968	81900
1969	89167
1970	90013
1971	93968
1972	95638
1973	100072
1974	102164
1975	104752
1976	109999
1977	114815
1978	121150
1979	130202
1980	130700
1981	135900
1982	139206
1983	144439
1984	145848
1985	150000
1986	154209
1987	150605
1988	153093
1989	154696
1990	153000
1991	151500
1992	150000
1993	149000
1994	148104
1995	146000
1996	143000
1997	140000
1998	137000
1999	134342
2000	134064
2001	133786
2002	133508
2003	133229
2004	132951
2005	132673