Year	Number
1970	93182
1971	114950
1972	132754
1973	163046
1974	174593
1975	186430
1976	190559
1977	177199
1978	165253
1979	56693
1980	51368
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	0
1990	0
1991	0
1992	0
1993	0
1994	0
1995	0
1996	0
1997	0
2003	59658
2004	62912
2005	57284
2006	48637
2007	49770
2008	42379
2009	14561
2010	23550
2011	31572
2012	30680
2013	44270
2014	37719
2015	37416
2016	45221
2017	48546
2018	55088