Year	Number
1973	880923
1974	795716
1975	745548
1976	703289
1977	673543
1978	659842
1979	676565
1980	661495
1981	672969
1982	705636
1983	752963
1984	740979
1985	752599
1986	731061
1987	700554
1988	674816
1989	647004
1990	639055
1991	574878
1992	536041
1993	566620
1994	575647
1995	568935
1996	591560
1997	616417
1999	479436
2000	437379
2001	334325
2002	272112
2003	242540
2004	203108
2005	183211
2006	167668
2007	153790
2008	100344
2009	29957
2010	31982
2011	27410
2012	26026
2015	24862
2016	27860