Year	Number of
1990	9594
1991	9224
1992	9854
1993	10560
1994	11160
1995	11770
1996	13120
1997	14160
1998	15770
1999	16540
2000	18080
2001	19300
2002	19930
2003	20130
2004	19940
2005	20570
2006	20370
2007	20160