Year	Number of
1990	17060
1991	21470
1992	25880
1993	30330
1994	35180
1995	40380
1996	44950
1997	49170
1998	51980
1999	54600
2000	57770
2001	59950
2002	61760
2003	61340
2004	60870
2005	59480
2006	57840
2007	56230