Year	US Dollars, Monthly Level
1988-01-01	-772790479.6955650
1989-01-01	-786833568.7060160
1990-01-01	-1283850784.3984500
1991-01-01	-1726558053.8387000
1992-01-01	-1735910998.3855000
1993-01-01	-1827301560.0415900
1994-01-01	-1861709665.3605700
1995-01-01	-2174883166.9428700
1996-01-01	-2063310873.7965900
1997-01-01	-2409840489.6194500
1998-01-01	-2191052947.9208200
1999-01-01	-2943436188.9947400
2000-01-01	-2910433543.0801196
2001-01-01	-2600052990.0497100
2002-01-01	-2438587340.2124800
2003-01-01	-2888054939.1797000
2004-01-01	-3802514768.4796400
2005-01-01	-3296962452.3793597
2006-01-01	-4172978031.4009800
2007-01-01	-5100443980.6220700
2008-01-01	-6490810860.8699410
2009-01-01	-4078908408.7592400
2010-01-01	-6022699208.7779700
2011-01-01	-8045928613.1655200
2012-01-01	-8443248797.0211100
2013-01-01	-8131447021.5787300
2014-01-01	-7511657823.8126600
2015-01-01	-6146974202.6066700
2016-01-01	-5958763769.4890300
2017-01-01	-6889922863.7747700