Year	U.S. dollars (Billions)
1980	-0.876
1981	-0.562
1982	-0.305
1983	-0.047
1984	-0.127
1985	-0.115
1986	-0.045
1987	-0.502
1988	-0.471
1989	-0.590
1990	-0.705
1991	-0.288
1992	-0.357
1993	0.898
1994	0.729
1995	-0.283
1996	0.066
1997	0.063
1998	0.281
1999	1.058
2000	-0.199
2001	-0.320
2002	-0.118
2003	0.132
2004	-0.132
2005	-0.275
2006	-0.501
2007	-1.058
2008	-1.961
2009	-1.633
2010	-2.370
2011	-3.819
2012	-4.216
2013	-4.842
2014	-6.378
2015	-4.421
2016	-4.038
2017	-5.740
2018	-4.989
2019	-5.258
2020	-4.792
2021	-5.744
2022	-5.932
2023	-4.287
2024	-4.502
2025	-4.616
2026	-4.827
2027	-5.188
2028	-5.584
2029	-5.992