Year	Total
1971	6899000000
1972	7621000000
1973	8652000000
1974	5510000000
1975	6057000000
1976	6707000000
1977	7363000000
1978	8270000000
1979	9212000000
1980	10040000000
1981	11210000000
1982	12510000000
1983	12980000000
1984	13410000000
1985	14290000000
1986	15080000000
1987	15710000000
1988	16830000000
1989	18820000000
1990	20390000000
1991	21990000000
1992	24060000000
1993	25520000000
1994	27790000000
1995	28470000000
1996	28490000000
1997	29660000000
1998	31680000000
1999	33360000000
2000	36120000000
2001	38110000000
2002	38550000000
2003	39990000000
2004	40860000000
2005	46150000000
2006	48380000000
2007	49890000000
2008	47460000000