Year	Number of
1990	496500
1991	448900
1992	420200
1993	502300
1994	472400
1995	501000
1996	582700
1997	672800
1998	721500
1999	867900
2000	1033000
2001	352600
2002	1189000
2003	1443000
2004	1547000
2005	1616000
2006	2061000