Year	Number
1971	25605
1972	24320
1973	23867
1974	25080
1975	25922
1976	26140
1977	24419
1978	22632
1979	25867
1980	26957
1981	28220
1982	28506
1983	28674
1984	30929
1985	35120
1986	37079
1987	44851
1988	46558
1992	34477
1994	20567
1996	17814
1997	18933
1998	9507
1999	9167
2000	6665
2001	3303
2002	1096
2005	1477
2012	690
2013	3441
2014	6197