Year	Number of
1990	10850
1991	12250
1992	13430
1993	14830
1994	16270
1995	17820
1996	19210
1997	21010
1998	23050
1999	25420
2000	28220
2001	31130
2002	33960
2003	36170
2004	37330
2005	37650
2006	37430
2007	37160