Year	constant 2015 US$
1993	4570000
1994	136840000
1995	87870000
1996	124060000
1997	124390000
1998	135180000
1999	363120000
2000	364220000
2001	361330000
2002	381900000
2003	322610000
2004	293060000
2005	244170000
2006	209830000
2007	193110000
2008	182380000
2009	177670000
2010	174130000
2011	165630000
2012	133650000
2013	173370000
2014	184690000
2015	213280000
2016	168350000
2017	148120000