Year	Number of
1990	2823
1991	4664
1992	6817
1993	9236
1994	11610
1995	13870
1996	15770
1997	17800
1998	19860
1999	22040
2000	24420
2001	26760
2002	28920
2003	30460
2004	31090
2005	31080
2006	30710
2007	30550