Year US Dollars, Sum Over Component Sub-periods 1980-01-01 2595000000 1981-01-01 3636000000 1982-01-01 3836000000 1983-01-01 3429000000 1984-01-01 3992000000 1985-01-01 4038000000 1986-01-01 4041000000 1987-01-01 3567000000 1988-01-01 3086000000 1989-01-01 2975000000 1990-01-01 2970000000 1991-01-01 3068000000 1992-01-01 2810000000 1993-01-01 2877000000 1994-01-01 3330000000 1995-01-01 4780000000 1996-01-01 5496000000 1997-01-01 6359000000 1998-01-01 8438000000 1999-01-01 8415000000 2000-01-01 8896000000 2001-01-01 8006000000 2002-01-01 6585000000 2003-01-01 6653000000 2004-01-01 8044000000 2005-01-01 11878000000 2006-01-01 14036000000 2007-01-01 18297000000 2008-01-01 16921000000 2009-01-01 12916000000 2010-01-01 15839000000 2011-01-01 14232000000 2012-01-01 14944000000 2013-01-01 16165000000