Year	Number of
1990	14560
1991	15580
1992	16690
1993	17860
1994	19020
1995	20150
1996	20840
1997	22640
1998	24100
1999	25540
2000	27270
2001	28920
2002	30870
2003	32940
2004	34580
2005	38260
2006	39110
2007	41940