Year	constant 2015 US$
1978	134470000
1985	12890000
1986	10460000
1987	26560000
1988	14010000
1989	13060000
1990	10920000
1991	11750000
1992	13430000
1993	18030000
1994	7120000
1995	15380000
1996	31850000
1997	121700000
1998	143600000
1999	279910000
2000	112400000
2001	182230000
2002	363070000
2003	162850000
2004	185490000
2005	95770000
2006	58430000
2007	100950000
2008	216280000
2009	63800000
2010	74340000
2011	96850000
2012	81440000
2013	86080000
2014	118500000
2015	127670000
2016	119650000
2017	121500000