Year	Number of
1990	0
1991	0
1992	0
1993	0
1994	0
1995	0
1996	0
1997	13
1998	103
1999	669
2000	2098
2001	3232
2002	3955
2003	4709
2004	5499
2005	6305
2006	7144
2007	7998