Year	Number of
1990	22830
1991	23070
1992	23320
1993	23570
1994	23810
1995	24030
1996	24340
1997	24640
1998	24920
1999	25060
2000	23980
2001	22700
2002	21060
2003	20220
2004	19440
2005	19980
2006	19750
2007	15410