Year	Total
1971	2737000000
1972	3085000000
1973	3515000000
1974	3757000000
1975	4384000000
1976	5074000000
1977	5681000000
1978	6542000000
1979	7033000000
1980	7158000000
1981	7284000000
1982	7885000000
1983	8992000000
1984	9416000000
1985	10130000000
1986	10780000000
1987	11910000000
1988	13810000000
1989	14830000000
1990	16400000000
1991	18240000000
1992	19290000000
1993	21790000000
1994	23290000000
1995	25330000000
1996	27580000000
1997	27850000000
1998	32950000000
1999	32520000000
2000	34550000000
2001	35660000000
2002	37200000000
2003	39110000000
2004	39600000000
2005	42310000000
2006	42470000000
2007	43130000000
2008	42690000000