Year	Number
1961	10748
1962	11806
1963	12891
1964	14086
1965	15535
1966	17843
1967	19076
1968	21656
1969	26900
1970	32200
1971	37500
1972	42800
1973	48100
1974	53300
1975	58600
1976	63900
1977	69200
1978	74400
1979	79700
1980	85000
1981	90300
1982	95600
1983	100800
1984	106100
1985	111400
1986	116700
1987	122000
1988	127200
1989	132548
1990	132000
1991	131473
1992	131000
1993	146589
1994	148000
1995	150087
1996	152000
1997	154393
1998	160000
1999	168495
2000	169810
2001	171130
2002	172450
2003	173800
2004	175150
2005	176394