Year	U.S. dollars (Billions)
1980	0.011
1981	0.009
1982	0.005
1983	0.004
1984	0.010
1985	0.006
1986	0.011
1987	0.006
1988	0.001
1989	0.003
1990	-0.006
1991	0.009
1992	-0.009
1993	-0.001
1995	-0.006
1996	-0.017
1997	0.004
1998	0.016
1999	0.002
2000	-0.002
2001	-0.006
2002	-0.009
2003	-0.008
2004	-0.007
2005	-0.029
2006	-0.010
2007	-0.003
2008	-0.005
2009	-0.017
2011	-0.017
2012	0.004
2013	-0.010
2014	0.056
2015	0.056
2016	0.019
2017	0.071
2018	0.076
2019	0.087
2020	0.071
2021	0.020
2022	-0.006
2023	0.029
2024	0.030
2025	0.030
2026	0.029
2027	0.029
2028	0.030
2029	0.031