Year	Number
1970	99558
1971	127448
1972	146819
1973	163141
1974	162048
1975	163105
1976	157989
1977	168823
1978	186092
1979	178301
1980	169129
1981	161809
1982	147096
1983	125200
1984	112186
1985	128647
1986	127060
1987	116037
1988	133941
1989	203981
1990	255396
1991	262563
1992	264177
1993	261358
1994	277226
1998	358278
1999	370016
2000	377958
2002	395557
2003	386832
2004	384355
2005	397673
2006	395420
2007	388921
2008	379115
2009	358291
2010	356071
2011	354097
2012	324596
2013	335298
2014	322195
2015	311532
2016	300280
2017	292757