Year	constant 2015 US$
1992	18120000
1993	38600000
1994	91250000
1995	81470000
1996	128520000
1997	114210000
1998	213190000
1999	162520000
2000	171870000
2001	236210000
2002	221370000
2003	183530000
2004	282800000
2005	277200000
2006	257340000
2007	230530000
2008	270450000
2009	383260000
2010	406090000
2011	306490000
2012	352250000
2013	349960000
2014	318230000
2015	424860000
2016	342560000
2017	297400000