Year	Number of
1990	8598
1991	13770
1992	15480
1993	17280
1994	18180
1995	19210
1996	19080
1997	19500
1998	19920
1999	19760
2000	20700
2001	21820
2002	23340
2003	23840
2004	23080
2005	22110
2006	20840
2007	19690