Year	US Dollars, Sum Over Component Sub-periods
1981-01-01	4998000000
1982-01-01	4862000000
1983-01-01	4311000000
1984-01-01	4239000000
1985-01-01	5135000000
1986-01-01	4256000000
1987-01-01	4440000000
1988-01-01	4606000000
1989-01-01	5439000000
1990-01-01	6056000000
1991-01-01	6564000000
1992-01-01	8100000000
1993-01-01	9846000000
1994-01-01	11416000000
1995-01-01	13540000000
1996-01-01	15139000000
1997-01-01	16607000000
1998-01-01	12088000000
1999-01-01	12376000000
2000-01-01	15637000000
2001-01-01	15880000000
2002-01-01	17045000000
2003-01-01	17400000000
2004-01-01	20856000000
2005-01-01	22049000000
2006-01-01	21394000000
2007-01-01	24328000000
2008-01-01	28245000000
2009-01-01	22896000000
2010-01-01	26090000000
2011-01-01	31323000000
2012-01-01	33444000000
2013-01-01	33988000000