Year	current US$
1995	168000000
1996	156000000
1997	162000000
1998	172000000
1999	174000000
2000	144000000
2001	174000000
2002	190000000
2003	209000000
2004	211000000
2005	242000000
2006	250000000
2007	531000000
2008	545000000
2009	464000000
2010	453000000
2011	469000000
2012	407000000
2013	439000000
2014	424000000
2015	369000000
2016	390000000
2017	420000000
2018	496000000