Year	Number of
1990	19680
1991	19030
1992	24490
1993	27480
1994	34750
1995	46910
1996	64010
1997	51480
1998	73910
1999	50040
2000	31470
2001	122900
2002	137500
2003	158300
2004	163300
2005	202000
2006	208600