Year	Number of
1990	11550
1991	12010
1992	13510
1993	15570
1994	17160
1995	19960
1996	21470
1997	22010
1998	23730
1999	24120
2000	24050
2001	24680
2002	24140
2003	24900
2004	25820
2005	25260
2006	24720
2007	24520