Year	U.S. dollars (Billions)
1980	-0.931
1981	-1.371
1982	-1.100
1983	-0.713
1984	-0.766
1985	-0.825
1986	-1.358
1987	-1.601
1988	-1.841
1989	-2.045
1990	-2.200
1991	-2.500
1992	-1.475
1993	-1.408
1994	-1.476
1995	-1.475
1996	-1.086
1997	-1.098
1998	-1.428
1999	-0.767
2000	-0.518
2001	-0.522
2002	-0.974
2003	-0.939
2004	-0.818
2005	-2.473
2006	-6.496
2007	-3.597
2008	-3.594
2009	-4.927
2010	-1.725
2011	-2.653
2012	-6.259
2013	-5.822
2014	-3.545
2015	-5.461
2016	-4.213
2017	-4.611
2018	-4.679
2019	-4.780
2020	-5.841
2021	-2.620
2022	-3.794
2023	-1.389
2024	-1.858
2025	-3.010
2026	-2.986
2027	-3.073
2028	-3.125
2029	-3.054