Year	Number of
1990	1109
1991	1542
1992	2152
1993	2936
1994	3982
1995	5290
1996	6965
1997	8905
1998	11070
1999	13380
2000	15660
2001	17850
2002	19800
2003	21450
2004	22800
2005	23860
2006	24670
2007	24700