Year	U.S. dollars (Billions)
1980	12.980
1981	16.652
1982	17.415
1983	18.649
1984	19.171
1985	21.177
1986	25.428
1987	32.497
1988	16.538
1989	9.849
1990	12.303
1991	12.738
1992	13.263
1993	13.796
1994	15.105
1995	16.556
1996	17.761
1997	16.573
1998	16.144
1999	16.785
2000	19.861
2001	20.979
2002	22.758
2003	21.702
2004	25.204
2005	28.881
2006	33.824
2007	40.488
2008	52.631
2009	53.939
2010	60.043