Year	Total
1973	6601000000
1974	6264000000
1975	6571000000
1976	6701000000
1977	6901000000
1978	7271000000
1979	7681000000
1980	7441000000
1981	7373000000
1982	7421000000
1983	8041000000
1984	8464000000
1985	9138000000
1986	9583000000
1987	9967000000
1988	9944000000
1989	9903000000
1990	9672000000
1991	10140000000
1992	10210000000
1993	10330000000
1994	10430000000
1995	10300000000
1996	10600000000
1997	10320000000
1998	10260000000
1999	10290000000
2000	10220000000
2001	10160000000
2002	10190000000
2003	10260000000
2004	10330000000
2005	10450000000
2006	10570000000
2007	10350000000
2008	10330000000
