Year	Total
1971	8089000000
1972	8390000000
1973	9267000000
1974	9768000000
1975	9993000000
1976	10480000000
1977	11300000000
1978	11720000000
1979	12330000000
1980	13520000000
1981	14740000000
1982	14620000000
1983	14490000000
1984	15700000000
1985	16400000000
1986	17650000000
1987	18680000000
1988	19580000000
1989	21520000000
1990	22450000000
1991	23080000000
1992	19400000000
1993	21550000000
1994	22120000000
1995	24370000000
1996	29560000000
1997	30730000000
1998	30170000000
1999	29520000000
2000	28690000000
2001	34630000000
2002	30420000000
2003	34080000000
2004	36240000000
2005	36980000000
2006	39680000000
2007	41180000000
2008	40290000000