Year	Number of
1990	9222
1991	14770
1992	16600
1993	18530
1994	19490
1995	20610
1996	20470
1997	15940
1998	16410
1999	16030
2000	17070
2001	17000
2002	18100
2003	19060
2004	18510
2005	18180
2006	17130
2007	16110