Year	Number
1971	33264
1972	33321
1973	32069
1974	32581
1975	33150
1976	33825
1977	29865
1978	20009
1979	23472
1980	26911
1981	26580
1982	25828
1983	22223
1984	20226
1985	17895
1986	18739
1987	28936
1988	33903
1992	105244
1994	51841
1996	14912
1997	15155
1998	6807
1999	7775
2000	12837
2001	13897
2002	10262
2003	11078
2004	8667
2005	14820
2007	4502
2008	2461
2010	2735
2011	1910
2012	3575
2013	5843
2014	6402
2015	6218
2016	8799