Year	Total
1971	334.5
1972	671.9
1973	2439
1974	2859
1975	2217
1976	2510
1977	2248
1978	2875
1979	3230
1980	3819
1981	4597
1982	5136
1983	5869
1984	6540
1985	6414
1986	6552
1987	6939
1988	7690
1989	8665
1990	8746
1991	8783
1992	9389
1993	10320
1994	9807
1995	10050
1996	11200
1997	12460
1998	13660
1999	14600
2000	14580
2001	13600
2002	13130
2003	12070
2004	12540
2005	13640
2006	15360
2007	12510
2008	13250
2009	15280