(十億美元)(十億美元)
1978 1.67 1995 735.97
1979 8.40 1996 1050.29
1980 -12.96 1997 1398.90
1981 27.08 1998 1449.59
1982 69.86 1999 1546.75
1983 89.01 2000 1655.74
1984 82.20 2001 2121.65
1985 26.44 2002 2864.07
1986 20.72 2003 4032.51
1987 29.23 2004 6099.32
1988 33.72 2005 8188.72
1989 55.50 2006 10663.40
1990 110.93 2007 15282.49
1991 217.12 2008 19460.30
1992 194.43 2009 23991.52
1993 211.99 2010 28473.38
1994 516.20 2011 31811.48