Year	Total
1971	2030000000
1972	2045000000
1973	2055000000
1974	2355000000
1975	2670000000
1976	3019000000
1977	3508000000
1978	3661000000
1979	4026000000
1980	4561000000
1981	5086000000
1982	5485000000
1983	6817000000
1984	7764000000
1985	8852000000
1986	9806000000
1987	10830000000
1988	11440000000
1989	12360000000
1990	13350000000
1991	14150000000
1992	14420000000
1993	15170000000
1994	15950000000
1995	16830000000
1996	17110000000
1997	17920000000
1998	19900000000
1999	21820000000
2000	23550000000
2001	25680000000
2002	27720000000
2003	29830000000
2004	31320000000
2005	33910000000
2006	36600000000
2007	40280000000
2008	43820000000