Year	Number of
1990	15920
1991	17950
1992	19560
1993	21420
1994	23290
1995	25300
1996	26570
1997	29450
1998	32040
1999	35510
2000	40110
2001	45110
2002	50420
2003	54760
2004	57560
2005	58650
2006	58980
2007	59510