Year	current US$
1994	1100000000
1996	853300000
1997	490000000
1998	660000000
1999	278000000
2001	1700000000
2002	14000000
2004	9000000
2005	3000000
2006	459000000
2007	13624200000
2008	13161970000
2009	1484320000
2010	5981920000
2011	5255570000
2012	464677000
2013	480000000
2014	723100000
2015	282000000
2016	207010000
2017	161000000
2018	487420000
2019	652310000
2020	486950000
2021	101020000