Year	U.S. dollars (Billions)
1980	-0.411
1981	-0.592
1982	-0.514
1983	-0.507
1984	-0.597
1985	-0.771
1986	-0.691
1987	-0.690
1988	-0.715
1989	-0.362
1990	-0.305
1991	-0.264
1992	-0.769
1993	-0.604
1994	-0.911
1995	-0.722
1996	-0.825
1997	-0.841
1998	-0.687
1999	-0.928
2000	-0.936
2001	-0.820
2002	-0.784
2003	-0.706
2004	-0.687
2005	-0.784
2006	-0.885
2007	-1.207
2008	-1.450
2009	-0.702
2010	-0.777
2011	-1.164
2012	-1.235
2013	-1.380
2014	-0.954
2015	-1.260
2016	-1.127
2017	-0.987
2018	-0.234
2019	0.754
2020	0.456
2021	-0.440
2022	-0.244
2023	0.791
2024	0.577
2025	0.393
2026	0.273
2027	0.258
2028	0.238
2029	0.238