Year	Number of
1980	5321
1981	6162
1982	6525
1983	6860
1984	7272
1985	8246
1986	8716
1987	10020
1988	12880
1989	14270
1990	16860
1991	23370
1992	25450
1993	30500
1994	35220
1995	35960
1996	40420
1999	45240
2000	49810
2001	46260
2002	54220
2003	53930
2004	54110
2005	49580
2006	47790
2007	46320