Year	Number of
1980	11810
1981	10610
1982	7741
1983	6970
1984	6807
1985	6485
1986	6846
1987	6517
1988	11380
1989	14310
1990	14740
1991	13530
1992	14900
1993	18550
1994	19730
1995	9697
1996	29200
1997	26610
1998	29410
1999	29900
2000	9697
2001	10480
2002	11900
2003	11660
2004	10500
2005	9454
2006	8043
2007	7863