Year	Number of
1990	175
1991	294
1992	404
1993	619
1994	2411
1995	6103
1996	16560
1997	29790
1998	19350
1999	13490
2000	19060
2001	11390
2002	6160
2003	5428
2004	1804
2005	1398
2006	776