Year	Number of
1990	0
1991	14
1992	15
1993	16
1994	17
1995	54
1996	278
1997	702
1998	1158
1999	1466
2000	1851
2001	2295
2002	2773
2003	3238
2004	3697
2005	4358
2006	4546
2007	4745