Year	US Dollars, Monthly Level
1960-01-01	74988456.21947850
1961-01-01	76026804.48318400
1962-01-01	83508540.14845900
1963-01-01	92349904.67990260
1964-01-01	110444379.11224100
1965-01-01	125304074.31603199
1966-01-01	138019359.47903900
1967-01-01	97333011.00194040
1968-01-01	78511337.28543490
1969-01-01	106466935.03645800
1970-01-01	146068534.51086200
1971-01-01	150297745.29463598
1972-01-01	190542271.59444300
1973-01-01	274707700.30052596
1974-01-01	332985112.85337500
1975-01-01	297441704.04247797
1976-01-01	394976410.91082800
1977-01-01	507536581.14808300
1978-01-01	642179509.78641400
1979-01-01	774412744.73989390
1980-01-01	911233985.34548600
1981-01-01	887154325.43617800
1982-01-01	685682366.35040200
1983-01-01	741529027.99075210
1984-01-01	732585217.19833500
1985-01-01	813055620.77891900
1986-01-01	1051499337.68357990
1987-01-01	1348581189.50451000
1988-01-01	1403357511.50001000
1989-01-01	1412493859.22680000
1990-01-01	1582394776.73443980
1991-01-01	1551942360.45898990
1992-01-01	1526985628.43204000
1993-01-01	1399942273.47508000
1994-01-01	1627471002.13575980
1995-01-01	1808724481.13073000
1996-01-01	1897540689.38870980
1997-01-01	1863767678.37924000
1998-01-01	1934945307.46431000
1999-01-01	1995667023.73008000
2000-01-01	1913962332.19047000
2001-01-01	2023672863.78719020
2002-01-01	2240871971.15593000
2003-01-01	2397690155.82900000
2004-01-01	2893826742.66395000
2005-01-01	3103437038.69517040
2006-01-01	3476432814.44942000
2007-01-01	4227752810.14459040
2008-01-01	5358157717.45281000
2009-01-01	4067205162.31468000
2010-01-01	4565949958.72616000
2011-01-01	5310006566.45838000
2012-01-01	4995772129.96813000
2013-01-01	4982471358.34841000
2014-01-01	5046461716.68891000
2015-01-01	4757663043.81250000
2016-01-01	4452472684.94332000
2017-01-01	4829848955.31317000