Year	Number of
1980	4412
1981	5072
1982	4777
1983	5178
1984	4131
1985	7679
1986	6837
1987	8960
1988	10660
1989	12560
1990	11170
1991	11220
1992	9520
1993	8614
1994	9431
1995	14420
1996	10190
1997	9853
1998	10130
1999	9863
2000	10130
2001	10530
2002	10200
2003	9836
2004	9801
2005	9748
2006	9014
2007	8574