Year	US Dollars, Monthly Level
1980-01-01	15511800000.000000
1981-01-01	20102100000.000000
1982-01-01	21229600000.000000
1983-01-01	22312100000.000000
1984-01-01	24195900000.000000
1985-01-01	21663800000.000000
1986-01-01	16157699999.999998
1987-01-01	20494600000.000000
1988-01-01	20545900000.000000
1989-01-01	22842200000.000000
1990-01-01	26838500000.000000
1991-01-01	42687520000.000000
1992-01-01	46195623000.000000
1993-01-01	51885969000.000000
1994-01-01	60882199000.000000
1995-01-01	79541554000.000000
1996-01-01	95999740000.000000
1997-01-01	110431498000.000000
1998-01-01	117539294000.000000
1999-01-01	136361816000.000000
2000-01-01	166120737000.000000
2001-01-01	158779733000.000000
2002-01-01	161045980000.000000
2003-01-01	164766436000.000000
2004-01-01	187998555000.000000
2005-01-01	214232956000.000000
2006-01-01	249925144000.000000
2007-01-01	271875312000.000000
2008-01-01	291342595000.000000
2009-01-01	229703550000.000000
2010-01-01	298473146000.000000
2011-01-01	349433386000.000000
2012-01-01	370769890000.000000
2013-01-01	380015051000.000000
2014-01-01	396911688000.000000
2015-01-01	380549593000.000000
2016-01-01	373946694000.000000
2017-01-01	409401075000.000000