Year	Number
1971	2829
1972	3085
1973	2794
1977	1182
1978	1100
1979	1000
1981	867
1982	731
1983	559
1984	745
1985	735
1986	738
1987	753
1988	731
1989	829
1990	717
1991	894
1992	551
1993	688
2004	892