Year	current US$
1997	29000000
1998	40000000
1999	53000000
2000	67000000
2001	80000000
2002	64000000
2003	88000000
2004	92000000
2005	447000000
2006	506000000
2007	599000000
2008	542000000
2009	474000000
2010	492000000
2011	555000000
2012	518000000
2013	552000000
2014	642000000
2015	660000000
2016	683000000
2017	653000000