Year	Total
1971	204000000
1972	228000000
1973	460100000
1974	554100000
1975	731100000
1976	914200000
1977	1138000000
1978	1351000000
1979	1667000000
1980	1667000000
1981	1667000000
1982	1667000000
1983	1667000000
1984	1667000000
1985	1667000000
1986	2223000000
1987	2779000000
1988	3057000000
1989	3057000000
1990	3057000000
1991	3144000000
1992	3314000000
1993	3416000000
1994	3336000000
1995	3291000000
1996	3177000000
1997	4174000000
1998	5741000000
1999	5671000000
2000	5966000000
2001	6709000000
2002	3599000000
2003	3736000000
2004	4038000000
2005	7083000000
2006	8048000000
2007	7085000000
2008	5223000000