Year US Dollars, Sum Over Component Sub-periods 1975-01-01 -1771200000 1976-01-01 -712400000 1977-01-01 386000000 1978-01-01 1041000000 1979-01-01 313600000 1980-01-01 -732100000 1981-01-01 428200000 1982-01-01 260700000 1983-01-01 246800000 1984-01-01 1626300000 1985-01-01 977800000 1986-01-01 1746000000 1987-01-01 1572900000 1988-01-01 1315200000 1989-01-01 -73500000 1990-01-01 909900000 1991-01-01 2477900000 1992-01-01 4002900000 1993-01-01 6439700000 1994-01-01 7732000000 1995-01-01 12581400000 1996-01-01 11625400000 1997-01-01 11823400000 1998-01-01 12757400000 1999-01-01 11806300000 2000-01-01 13469700000 2001-01-01 12265700000 2002-01-01 12315000000 2003-01-01 12388700000 2004-01-01 12144900000 2005-01-01 9137500000 2006-01-01 10827000000 2007-01-01 12499600000 2008-01-01 9926000000 2009-01-01 4213500000 2010-01-01 3388000000 2011-01-01 -1748000000 2012-01-01 -117900000 2013-01-01 172600000