Year	current US$
1997	157292000000
1998	163276000000
1999	157842000000
2000	177008000000
2001	178721000000
2002	198223000000
2003	234967000000
2004	285610000000
2005	318588000000
2006	351569000000
2007	412010000000
2008	467381000000
2009	354782000000
2010	391278000000
2011	466916000000
2012	439535000000
2013	451584000000
2014	453700000000
2015	375530000000
2016	379409000000
2017	409220000000
2018	454947000000
2019	427708000000
2020	396132000000