Year	Number
1970	12361
1971	16468
1972	17649
1973	22098
1975	7140
1976	11751
1977	8848
1978	7902
1979	12013
1980	13839
1981	14242
1982	16361
1983	17132
1984	16172
1985	21161
1986	23438
1987	27349
1988	29604
1989	30344
1990	29102
1991	28871
1992	28155
1993	24954
1994	12492
1995	9476
2007	27831
2008	26998
2009	26832