Year	Total
1971	5938
1972	6242
1973	6149
1974	4271
1975	6577
1976	88.09
1977	77.93
1978	74.43
1979	85.78
1980	153.5
1981	150.1
1982	78.87
1983	68.08
1984	55.95
1985	282.2
1986	341.1
1987	362.3
1988	379.5
1989	390.6
1990	424.1
1991	438.1
1992	458
1993	502
1994	516.2
1995	547.7
1996	556.9
1997	584
1998	600.4
1999	600.5
2000	642
2001	672.6
2002	708.3
2003	738.6
2004	1742
2005	2109
2006	2683
2007	2899
2008	3900
2009	3266
2010	3730