Year	Number of
1990	9586
1991	10240
1992	11120
1993	12120
1994	13060
1995	13820
1996	14370
1997	14750
1998	15020
1999	15310
2000	15700
2001	16220
2002	16820
2003	17500
2004	18230
2005	18980
2006	19750
2007	20550