Year	Number
1970	525155
1973	483688
1980	404471
1981	258601
1982	240582
1985	141680
1988	293715
1993	210406
1995	394842
1996	417366
1997	440460
1998	7748
1999	1201
2000	1674
2001	9095
2002	10214
2003	16360
2004	30910
2005	36690
2006	37144
2007	38360
2008	41654
2009	38161
2010	38268
2011	48600
2012	238112
2013	145229
2014	161745
2015	72898
2016	19945