Year	Number
1961	2524044
1962	2752021
1963	2995848
1964	3238661
1965	3450561
1966	3679555
1967	3884616
1968	4095265
1969	4301841
1970	4432797
1971	4619683
1972	4759359
1973	4886992
1974	5008998
1975	5143357
1976	5270227
1977	5415326
1978	5547042
1979	5696063
1980	5891292
1981	5990402
1982	6092679
1983	6186929
1984	6249393
1985	6312156
1986	6389984
1987	6457094
1988	6537778
1989	6563569
1990	6555235
1991	6507129
1992	6559522
1993	6603989
1994	6582360
1995	6572323
1996	6571163
1997	6530790
1998	6522149
1999	6512397
2000	6498712.5
2001	5584482
2002	5651097
2003	3866603
2004	3855765
2005	3845635