Year	Number of
1980	1637
1981	1306
1982	1805
1983	1932
1984	1572
1985	1308
1986	1209
1987	22060
1988	1378
1989	1492
1990	2142
1991	3634
1992	8876
1993	3426
1994	3911
1995	11140
1996	12340
1997	13970
1998	12660
1999	11760
2000	10760
2001	10550
2002	11180
2003	11490
2004	11620
2005	11450
2006	10050
2007	9841