Year	Number of
1980	2576
1981	1980
1982	8158
1983	7572
1984	10240
1985	10140
1986	10320
1987	9106
1988	10690
1989	7906
1990	6501
1991	10900
1992	16150
1993	13270
1994	15170
1995	14600
1996	14860
1997	15630
1998	16950
1999	19270
2000	18890
2001	19170
2002	24610
2003	28220
2004	30840
2005	35540
2006	34660
2007	35600