Year	current US$
1998	138000000
1999	135000000
2000	155000000
2001	150000000
2002	154000000
2003	160000000
2004	134000000
2005	119000000
2006	183000000
2007	275000000
2008	319000000
2009	364000000
2010	368000000
2011	396000000
2012	409000000
2013	356000000
2014	404000000
2015	432000000
2016	441000000
2017	423000000
2018	496000000
2019	337000000