Year	current US$
1995	18000000
1996	15000000
1997	14000000
1998	15000000
1999	1000000
2000	2000000
2001	15000000
2002	45000000
2005	168000000
2006	144000000
2007	516000000
2008	845000000
2009	1405000000
2010	1660000000
2011	1543000000
2012	1634000000
2013	1682000000
2014	1938000000
2015	2833000000
2016	3120000000
2017	2959000000
2018	1986000000
2019	3593000000
2020	955000000