Year	Number of
1953	186300
1954	191100
1955	195800
1956	199100
1957	202700
1958	205800
1959	207800
1960	209400
1961	209300
1962	208500
1963	207900
1964	207300
1965	207800
1966	209100
1967	211000
1968	213100
1969	214700
1970	215200
1971	213600
1972	211100
1973	207700
1974	204100
1975	200800
1976	197000
1977	193900
1978	191300
1979	188700
1980	185900
1981	182500
1982	179000
1983	175100
1984	170400
1985	165700
1986	159800
1987	154000
1988	148100
1989	142700
1990	137900
1991	134400
1992	131800
1993	129600
1994	126600
1995	122400
1996	117300
1997	111600
1998	106300
1999	101300
2000	97000
2001	93970
2002	91460
2003	89650
2004	88240
2005	86010
2006	83550
2007	81230
2008	79020
2009	77430
2010	75790
2011	75350
2012	75960
2013	76300
2014	75980
2015	73920