Quarter	Millions of US Dollars
1972-10-01	20
1973-01-01	35
1973-04-01	35
1973-07-01	35
1973-10-01	35
1974-01-01	35
1974-04-01	35
1974-07-01	35
1974-10-01	35
1975-01-01	35
1975-04-01	35
1975-07-01	35
1975-10-01	35
1976-01-01	35
1976-04-01	35
1976-07-01	35
1976-10-01	35
1977-01-01	35
1977-04-01	35
1977-07-01	35
1977-10-01	35
1978-01-01	35
1978-04-01	35
1978-07-01	35
1978-10-01	35
1979-01-01	35
1979-04-01	35
1979-07-01	35
1979-10-01	35
1980-01-01	35
1980-04-01	35
1980-07-01	35
1980-10-01	35
1981-01-01	35
1981-04-01	35
1981-07-01	65
1981-10-01	65
1982-01-01	65
1982-04-01	65
1982-07-01	65
1982-10-01	115
1983-01-01	115
1983-04-01	115
1983-07-01	115
1983-10-01	115
1984-01-01	115
1984-04-01	115
1984-07-01	115
1984-10-01	95
1985-01-01	144
1985-04-01	144
1985-07-01	331
1985-10-01	336
1986-01-01	340
1986-04-01	343
1986-07-01	349
1986-10-01	172
1987-01-01	178
1987-04-01	177
1987-07-01	258
1987-10-01	285
1988-01-01	261
1988-04-01	355
1988-07-01	346
1988-10-01	362
1989-01-01	344
1989-04-01	336
1989-07-01	348
1989-10-01	515
1990-01-01	604
1990-04-01	616
1990-07-01	660
1990-10-01	900
1991-01-01	841
1991-04-01	1196
1991-07-01	1254
1991-10-01	1378
1992-01-01	1294
1992-04-01	1686
1992-07-01	1781
1992-10-01	1680
1993-01-01	1697
1993-04-01	1812
1993-07-01	2174
1993-10-01	2190
1994-01-01	2354
1994-04-01	2440
1994-07-01	2613
1994-10-01	2535
1995-01-01	3097
1995-04-01	3030
1995-07-01	2623
1995-10-01	2667
1996-01-01	2593
1996-04-01	2523
1996-07-01	2487
1996-10-01	2397
1997-01-01	2394
1997-04-01	2553
1997-07-01	2344
1997-10-01	1959
1998-01-01	1555
1998-04-01	1698
1998-07-01	1955
1998-10-01	2165
1999-01-01	2818
1999-04-01	2695
1999-07-01	2927
1999-10-01	2673
2000-01-01	2692
2000-04-01	2684
2000-07-01	2617
2000-10-01	3423
2001-01-01	3259
2001-04-01	3297
2001-07-01	3496
2001-10-01	3268
2002-01-01	3410
2002-04-01	3836
2002-07-01	3988
2002-10-01	4481
2003-01-01	4619
2003-04-01	5284
2003-07-01	5147
2003-10-01	5785
2004-01-01	5416
2004-04-01	5374
2004-07-01	6037
2004-10-01	7110
2005-01-01	7282
2005-04-01	6826
2005-07-01	6719
2005-10-01	6751
2006-01-01	6913
2006-04-01	8065
2006-07-01	8028
2006-10-01	10587
2007-01-01	9510
2007-04-01	9826
2007-07-01	10116
2007-10-01	10149
2008-01-01	11251
2008-04-01	10948
2008-07-01	9986
2008-10-01	9747
2009-01-01	8671
2009-04-01	8818
2009-07-01	8949
2009-10-01	8810
2010-01-01	8390
2010-04-01	7709
2010-07-01	8500
2010-10-01	7057
2011-01-01	7454
2011-04-01	7574
2011-07-01	6726
2011-10-01	6242
2012-01-01	6375
2012-04-01	6056
2012-07-01	5823
2012-10-01	5459
2013-01-01	4873
2013-04-01	4531
2013-07-01	5447
2013-10-01	5840
2014-01-01	5568
2014-04-01	6633
2014-07-01	5990
2014-10-01	5812
2015-01-01	3894
2015-04-01	3797
2015-07-01	3577
2015-10-01	3282
2016-01-01	3394
2016-04-01	3330
2016-07-01	3193
2016-10-01	3053
2017-01-01	2606
2017-04-01	2608
2017-07-01	2434
2017-10-01	2311
2018-01-01	2352
2018-04-01	2403