Year	US Dollars, Monthly Level
1990-01-01	23555421119.182700
1991-01-01	20486718911.486000
1992-01-01	21740042430.723300
1993-01-01	22321139312.198500
1994-01-01	26842113345.156498
1995-01-01	34730839327.061400
1996-01-01	37915809821.023600
1997-01-01	41417249035.675300
1998-01-01	42968639686.138800
1999-01-01	46894910943.605194
2000-01-01	51677816983.138300
2001-01-01	50306682948.730300
2002-01-01	56407161375.907104
2003-01-01	72425557983.994600
2004-01-01	99567768259.829400
2005-01-01	142833879335.380000
2006-01-01	178239814906.826020
2007-01-01	228697694066.343000
2008-01-01	320042784985.166000
2009-01-01	256574932564.973000
2010-01-01	350230069977.467000
2011-01-01	464284131064.187000
2012-01-01	489623260205.258000
2013-01-01	465207241074.239000
2014-01-01	462742626976.384000
2015-01-01	393619962140.720030
2016-01-01	361675695868.148000
2017-01-01	449822834875.758000