Year	current US$
1993	2300000000
1997	4608000000
1998	1370000000
2001	689000000
2003	360000000
2011	342750000
2012	1880000000
2013	1438000000
2014	2621580000
2015	1900000000
2017	220000000
2018	261860000
2019	25800000
2020	1038770000
2022	167920000