Year	US Dollars, Monthly Level
1999-01-01	4386410000000
2000-01-01	4939630000000
2001-01-01	4719930000000
2002-01-01	4870490000000
2003-01-01	5641020000000
2004-01-01	6709960000000
2005-01-01	7517230000000
2006-01-01	8534770000000
2007-01-01	9688770000000
2008-01-01	10853430000000
2009-01-01	8166060000000
2010-01-01	9623230000000
2011-01-01	11357240000000
2012-01-01	11111050000000
2013-01-01	11142670000000
2014-01-01	11342170000000
2015-01-01	10017620000000
2016-01-01	9811080000000