Year	Number of
1980	11590
1981	11480
1982	12130
1983	13720
1984	12790
1985	12020
1986	11640
1987	11440
1988	11470
1989	11330
1990	12450
1991	12260
1992	11200
1993	11040
1994	8901
1995	9912
1996	9702
1997	8042
1998	9155
1999	11000
2000	11630
2001	11480
2002	11380
2003	11640
2004	11240
2005	10360
2006	11130
2007	10950