Year	U.S. dollars (Billions)
1980	-0.915
1981	-0.850
1982	-0.374
1983	-0.568
1984	-1.120
1985	-0.848
1986	-0.593
1987	-0.985
1988	-1.374
1989	-1.493
1990	-1.378
1991	-1.723
1992	-1.066
1993	-3.354
1994	-1.660
1995	-2.168
1996	-4.172
1997	-3.598
1998	-1.704
1999	-1.856
2000	-0.215
2001	0.324
2002	2.833
2003	4.070
2004	1.831
2005	-1.474
2006	-4.899
2007	-6.772
2008	-13.788
2009	-9.260
2010	-3.946
2011	0.214
2012	-4.658
2013	-2.496
2014	-3.130
2015	-2.815
2016	-4.961
2017	-12.270
2018	-19.195
2019	-13.434
2020	-4.449
2021	-2.820
2022	-17.481
2023	-2.235