Year	U.S. dollars (Billions)
1980	1.116
1981	1.377
1982	0.503
1983	0.506
1984	0.319
1985	0.006
1986	-1.027
1987	0.790
1988	-0.307
1989	0.349
1990	1.099
1991	-0.197
1992	-0.558
1993	-1.377
1994	-0.753
1995	-0.818
1996	0.206
1997	-0.195
1998	-3.121
1999	-0.461
2000	3.130
2001	1.977
2002	1.699
2003	1.453
2004	0.902
2005	5.178
2006	5.662
2007	2.462
2008	5.047
2009	-0.500
2010	4.936
2011	8.868
2012	7.859
2013	5.288
2014	4.292
2015	-10.833
2016	-12.437
2017	-11.008
2018	-4.459
2019	-4.318
2020	-12.514
2021	-4.834
2022	5.652
2023	1.954
2024	2.960
2025	2.337
2026	2.241
2027	2.078
2028	2.405
2029	2.363