Year	Number of
1990	8531
1991	10730
1992	12940
1993	15160
1994	17590
1995	20190
1996	22470
1997	24580
1998	25990
1999	27300
2000	28890
2001	29970
2002	30880
2003	30670
2004	30440
2005	29740
2006	28920
2007	28120