Year	Number of
1990	11680
1991	11860
1992	12050
1993	12250
1994	12460
1995	12680
1996	12910
1997	13150
1998	13380
1999	13610
2000	13840
2001	14070
2002	14300
2003	14520
2004	14760
2005	14990
2006	15220
2007	15460