Year	Number of
1980	31250
1981	32570
1982	24850
1983	22800
1984	14530
1985	15020
1986	13180
1987	14630
1988	15370
1989	15490
1990	14440
1991	15220
1992	14450
1993	15140
1994	16350
1995	11330
1996	20720
1997	23580
1998	21510
1999	19800
2000	18430
2001	18880
2002	17790
2003	17080
2004	15100
2005	18520
2006	17890
2007	18320