Year	current US$
1996	116000000
1997	136000000
1998	143000000
1999	164000000
2000	181000000
2001	176000000
2002	196000000
2003	224000000
2004	281000000
2005	230000000
2006	339000000
2007	374000000
2008	551000000
2009	402000000
2010	574000000
2011	487000000
2012	585000000
2013	958000000
2014	382000000
2015	400000000
2016	359000000
2017	524000000
2018	452000000
2019	469000000
2020	265000000