Year	US Dollars
1977	117700000
1978	126100000
1979	98800000
1980	100200000
1981	71500000
1982	98400000
1983	148200000
1984	107800000
1985	128100000
1986	146200000
1987	149800000
1989	-102190000
1990	-56940000
1991	-131180000
1992	-30080000
1993	17730000
1994	-76880000
1995	-184040000
1996	-353010000
1997	-378300000
1998	-574800000
1999	-214300000
2000	-286700000
2001	-362300000
2002	184100000
2003	49400000
2004	38800000
2005	-381300000
2006	-1111500000
2007	-831300000
2008	-888600000
2009	-812500000
2010	-885300000
2011	-1355800000
2012	-857300000
2013	-596800000
2014	-1312700000
2015	-439200000
2016	-221300000
2017	-991800000