Year	Number of
1990	287400
1991	400300
1992	399300
1993	327000
1994	273400
1995	142300
1996	184300
1997	218600
1998	211700
2000	210000
2001	66520
2002	41410
2003	10510
2004	3720
2005	1640
2006	591