Year	Number
1970	733685
1971	734147
1972	726211
1973	754928
1974	688769
1975	665728
1976	646113
1977	646105
1978	670560
1979	685829
1980	679915
1981	728013
1982	729219
1983	803931
1984	808546
1985	833643
1986	738013
1987	676909
1988	652966
1989	672780
1990	697014
1991	749461
1992	748664
1993	689434
1994	584513
1995	541332
1996	484818
1997	437278
1998	228835
1999	233309
2000	264016
2001	249858
2002	261115
2003	275588
2004	301152
2005	218044
2006	221589
2007	210114
2008	163205
2009	181499
2010	171584
2011	165560
2012	163776
2013	160467
2014	215253
2015	195300
2016	222718
2017	251804
2018	373598