Quarter	Millions of US Dollars
1966-01-01	0
1966-04-01	0
1966-07-01	0
1966-10-01	0
1967-01-01	0
1967-04-01	0
1967-07-01	0
1967-10-01	0
1968-01-01	0
1968-04-01	0
1968-07-01	0
1968-10-01	0
1969-01-01	0
1969-04-01	0
1969-07-01	0
1969-10-01	0
1970-01-01	0
1970-04-01	0
1970-07-01	0
1970-10-01	0
1971-01-01	0
1971-04-01	0
1971-07-01	0
1971-10-01	0
1972-01-01	0
1972-04-01	0
1972-07-01	0
1972-10-01	0
1973-01-01	0
1973-04-01	0
1973-07-01	0
1973-10-01	0
1974-01-01	0
1974-04-01	0
1974-07-01	0
1974-10-01	0
1975-01-01	0
1975-04-01	0
1975-07-01	0
1975-10-01	0
1976-01-01	0
1976-04-01	0
1976-07-01	0
1976-10-01	0
1977-01-01	0
1977-04-01	0
1977-07-01	0
1977-10-01	0
1978-01-01	28
1978-04-01	27
1978-07-01	93
1978-10-01	147
1979-01-01	113
1979-04-01	141
1979-07-01	243
1979-10-01	183
1980-01-01	167
1980-04-01	153
1980-07-01	100
1980-10-01	151
1981-01-01	180
1981-04-01	212
1981-07-01	184
1981-10-01	145
1982-01-01	231
1982-04-01	464
1982-07-01	427
1982-10-01	456
1983-01-01	327
1983-04-01	288
1983-07-01	462
1983-10-01	489
1984-01-01	499
1984-04-01	289
1984-07-01	77
1984-10-01	415
1985-01-01	546
1985-04-01	896
1985-07-01	1124
1985-10-01	1422
1986-01-01	1394
1986-04-01	1228
1986-07-01	1336
1986-10-01	1115
1987-01-01	1510
1987-04-01	1338
1987-07-01	1197
1987-10-01	1071
1988-01-01	1161
1988-04-01	1224
1988-07-01	1720
1988-10-01	1983
1989-01-01	1436
1989-04-01	1345
1989-07-01	788
1989-10-01	1181
1990-01-01	905
1990-04-01	750
1990-07-01	904
1990-10-01	1657
1991-01-01	1459
1991-04-01	2803
1991-07-01	3256
1991-10-01	2741
1992-01-01	3431
1992-04-01	2724
1992-07-01	3126
1992-10-01	2981
1993-01-01	2485
1993-04-01	2574
1993-07-01	3249
1993-10-01	3080
1994-01-01	3364
1994-04-01	2751
1994-07-01	2962
1994-10-01	2826
1995-01-01	2318
1995-04-01	1788
1995-07-01	2247
1995-10-01	2533
1996-01-01	3225
1996-04-01	3672
1996-07-01	2473
1996-10-01	3799
1997-01-01	2857
1997-04-01	2587
1997-07-01	2054
1997-10-01	3003
1998-01-01	2632
1998-04-01	2464
1998-07-01	2210
1998-10-01	2114
1999-01-01	1578
1999-04-01	1647
1999-07-01	2407
1999-10-01	2470
2000-01-01	2577
2000-04-01	2150
2000-07-01	1546
2000-10-01	2199
2001-01-01	2583
2001-04-01	3345
2001-07-01	3274
2001-10-01	2889
2002-01-01	2703
2002-04-01	2964
2002-07-01	3422
2002-10-01	2221
2003-01-01	3209
2003-04-01	2564
2003-07-01	1936
2003-10-01	2147
2004-01-01	2451
2004-04-01	3316
2004-07-01	3705
2004-10-01	4917
2005-01-01	3888
2005-04-01	3233
2005-07-01	3184
2005-10-01	2347
2006-01-01	1864
2006-04-01	1931
2006-07-01	1894
2006-10-01	1489
2007-01-01	1939
2007-04-01	1617
2007-07-01	1358
2007-10-01	2766
2008-01-01	2678
2008-04-01	1736
2008-07-01	1093
2008-10-01	379
2009-01-01	341
2009-04-01	672
2009-07-01	538
2009-10-01	666
2010-01-01	966
2010-04-01	707
2010-07-01	757
2010-10-01	1552
2011-01-01	2134
2011-04-01	1644
2011-07-01	3751
2011-10-01	3153
2012-01-01	3259
2012-04-01	3256
2012-07-01	1144
2012-10-01	3074
2013-01-01	8678
2013-04-01	6676
2013-07-01	7083
2013-10-01	6479
2014-01-01	1544
2014-04-01	1587
2014-07-01	1153
2014-10-01	710
2015-01-01	769
2015-04-01	1009
2015-07-01	4111
2015-10-01	10373
2016-01-01	11597
2016-04-01	11243
2016-07-01	8173
2016-10-01	2199
2017-01-01	1061
2017-04-01	1065
2017-07-01	884
2017-10-01	447
2018-01-01	637
2018-04-01	774