Year	current US$
1995	7611000000
1996	7402000000
1997	6326000000
1998	4603000000
1999	5089000000
2000	5142000000
2001	4641000000
2002	4458000000
2003	3842000000
2004	5327000000
2005	6209000000
2006	7536000000
2007	9066000000
2008	10615000000
2009	9225000000
2010	14178000000
2011	17929000000
2012	18795000000
2013	19231000000
2014	19161000000
2015	16617000000
2016	18944000000
2017	19891000000
2018	20416000000