Quarter	Millions of US Dollars
1972-04-01	25
1972-07-01	25
1972-10-01	25
1973-01-01	28
1973-04-01	73
1973-07-01	74
1973-10-01	84
1974-01-01	105
1974-04-01	121
1974-07-01	118
1974-10-01	128
1975-01-01	156
1975-04-01	155
1975-07-01	144
1975-10-01	146
1976-01-01	148
1976-04-01	148
1976-07-01	153
1976-10-01	155
1977-01-01	192
1977-04-01	232
1977-07-01	322
1977-10-01	347
1978-01-01	504
1978-04-01	632
1978-07-01	782
1978-10-01	921
1979-01-01	1044
1979-04-01	1014
1979-07-01	1254
1979-10-01	1222
1980-01-01	1138
1980-04-01	1278
1980-07-01	1399
1980-10-01	1383
1981-01-01	1323
1981-04-01	1273
1981-07-01	1312
1981-10-01	1444
1982-01-01	1638
1982-04-01	1795
1982-07-01	1787
1982-10-01	2305
1983-01-01	2314
1983-04-01	2528
1983-07-01	3737
1983-10-01	3798
1984-01-01	4235
1984-04-01	4158
1984-07-01	4225
1984-10-01	4873
1985-01-01	4911
1985-04-01	5836
1985-07-01	6125
1985-10-01	7648
1986-01-01	8242
1986-04-01	8454
1986-07-01	8510
1986-10-01	8442
1987-01-01	8757
1987-04-01	8734
1987-07-01	8824
1987-10-01	9732
1988-01-01	9724
1988-04-01	8966
1988-07-01	9102
1988-10-01	9570
1989-01-01	9337
1989-04-01	8788
1989-07-01	8936
1989-10-01	9187
1990-01-01	8868
1990-04-01	9549
1990-07-01	9910
1990-10-01	9621
1991-01-01	9269
1991-04-01	9272
1991-07-01	9383
1991-10-01	9466
1992-01-01	9384
1992-04-01	9389
1992-07-01	9637
1992-10-01	11356
1993-01-01	11691
1993-04-01	11756
1993-07-01	10765
1993-10-01	10309
1994-01-01	11741
1994-04-01	11273
1994-07-01	11829
1994-10-01	11356
1995-01-01	11903
1995-04-01	11445
1995-07-01	11095
1995-10-01	11104
1996-01-01	11546
1996-04-01	11688
1996-07-01	13331
1996-10-01	14140
1997-01-01	13969
1997-04-01	15352
1997-07-01	15263
1997-10-01	16217
1998-01-01	16182
1998-04-01	20653
1998-07-01	20391
1998-10-01	21625
1999-01-01	23115
1999-04-01	24668
1999-07-01	24457
1999-10-01	25717
2000-01-01	26320
2000-04-01	26617
2000-07-01	26963
2000-10-01	27651
2001-01-01	26988
2001-04-01	28705
2001-07-01	29230
2001-10-01	29549
2002-01-01	31401
2002-04-01	31227
2002-07-01	33872
2002-10-01	33656
2003-01-01	34385
2003-04-01	34625
2003-07-01	35283
2003-10-01	37322
2004-01-01	37844
2004-04-01	38873
2004-07-01	40470
2004-10-01	42488
2005-01-01	43395
2005-04-01	45376
2005-07-01	44874
2005-10-01	46576
2006-01-01	51502
2006-04-01	51073
2006-07-01	52053
2006-10-01	51163
2007-01-01	53711
2007-04-01	52395
2007-07-01	52246
2007-10-01	52371
2008-01-01	55227
2008-04-01	53865
2008-07-01	53340
2008-10-01	51784
2009-01-01	56367
2009-04-01	58821
2009-07-01	60080
2009-10-01	60765
2010-01-01	64601
2010-04-01	65706
2010-07-01	67210
2010-10-01	69810
2011-01-01	71435
2011-04-01	73608
2011-07-01	77775
2011-10-01	77065
2012-01-01	81839
2012-04-01	90305
2012-07-01	92474
2012-10-01	93846
2013-01-01	92491
2013-04-01	94280
2013-07-01	97625
2013-10-01	98448
2014-01-01	102861
2014-04-01	106059
2014-07-01	105199
2014-10-01	110764
2015-01-01	117518
2015-04-01	115667
2015-07-01	124696
2015-10-01	130970
2016-01-01	134038
2016-04-01	141830
2016-07-01	141636
2016-10-01	145242
2017-01-01	148888
2017-04-01	150759
2017-07-01	159351
2017-10-01	168946
2018-01-01	170212
2018-04-01	174888