Year	Total
1971	1384
1972	5300
1973	11900
1974	10250
1975	9469
1976	10840
1977	10720
1978	11600
1979	11920
1980	11750
1981	12050
1982	11940
1983	13650
1984	14940
1985	15980
1986	16430
1987	10560
1988	17110
1989	16030
1990	16470
1991	17280
1992	18360
1993	19690
1994	21490
1995	22130
1996	21890
1997	21970
1998	21440
1999	21440
2000	22650
2001	22990
2002	22200
2003	23710
2004	29310
2005	29420
2006	29890
2007	28910
2008	28550
2009	27320