Year	current US$
1997	156000000
1998	226000000
1999	130000000
2000	110000000
2001	107000000
2002	149000000
2003	130000000
2004	147000000
2005	169000000
2006	167000000
2007	176000000
2008	203000000
2009	181000000
2010	199000000
2011	213000000
2012	256000000
2013	294000000
2014	299000000
2015	330000000
2016	386000000
2017	464000000
2018	525000000
2019	657000000
2020	180000000