Year	Number of
1990	13430
1991	15100
1992	16350
1993	17780
1994	19230
1995	20850
1996	22330
1997	24320
1998	26580
1999	29170
2000	32160
2001	35140
2002	37910
2003	39910
2004	40740
2005	40740
2006	40240
2007	39780