Year	constant 2015 US$
1992	1620000
1993	10760000
1994	36570000
1995	84540000
1996	93780000
1997	154100000
1998	182550000
1999	179150000
2000	220090000
2001	207060000
2002	248760000
2003	230820000
2004	267490000
2005	181920000
2006	162170000
2007	168940000
2008	170740000
2009	178750000
2010	222970000
2011	183680000
2012	236240000
2013	269180000
2014	296420000
2015	460920000
2016	457250000
2017	638800000