Quarter	Millions of US Dollars
1973-07-01	26
1973-10-01	31
1974-01-01	33
1974-04-01	33
1974-07-01	34
1974-10-01	40
1975-01-01	64
1975-04-01	64
1975-07-01	60
1975-10-01	62
1976-01-01	64
1976-04-01	65
1976-07-01	66
1976-10-01	67
1977-01-01	65
1977-04-01	109
1977-07-01	133
1977-10-01	141
1978-01-01	144
1978-04-01	144
1978-07-01	101
1978-10-01	87
1979-01-01	84
1979-04-01	82
1979-07-01	84
1979-10-01	85
1980-01-01	82
1980-04-01	85
1980-07-01	84
1980-10-01	82
1981-01-01	99
1981-04-01	96
1981-07-01	148
1981-10-01	184
1982-01-01	182
1982-04-01	181
1982-07-01	250
1982-10-01	331
1983-01-01	428
1983-04-01	722
1983-07-01	831
1983-10-01	1181
1984-01-01	1573
1984-04-01	2265
1984-07-01	2393
1984-10-01	2664
1985-01-01	3178
1985-04-01	3663
1985-07-01	4644
1985-10-01	5263
1986-01-01	5426
1986-04-01	5851
1986-07-01	6359
1986-10-01	6677
1987-01-01	7115
1987-04-01	7165
1987-07-01	7036
1987-10-01	7235
1988-01-01	7462
1988-04-01	7443
1988-07-01	7542
1988-10-01	7628
1989-01-01	8278
1989-04-01	8337
1989-07-01	8331
1989-10-01	8158
1990-01-01	8274
1990-04-01	7822
1990-07-01	8660
1990-10-01	8351
1991-01-01	8956
1991-04-01	8568
1991-07-01	8669
1991-10-01	8652
1992-01-01	7804
1992-04-01	7758
1992-07-01	7670
1992-10-01	7501
1993-01-01	7407
1993-04-01	7652
1993-07-01	9623
1993-10-01	11266
1994-01-01	12193
1994-04-01	12830
1994-07-01	13953
1994-10-01	16319
1995-01-01	16757
1995-04-01	17234
1995-07-01	17109
1995-10-01	19065
1996-01-01	17846
1996-04-01	16665
1996-07-01	18329
1996-10-01	19915
1997-01-01	21513
1997-04-01	24240
1997-07-01	24977
1997-10-01	24348
1998-01-01	23947
1998-04-01	23951
1998-07-01	24376
1998-10-01	24713
1999-01-01	27642
1999-04-01	26471
1999-07-01	29394
1999-10-01	29811
2000-01-01	28262
2000-04-01	27081
2000-07-01	27932
2000-10-01	29549
2001-01-01	29187
2001-04-01	31739
2001-07-01	31346
2001-10-01	30308
2002-01-01	34012
2002-04-01	36817
2002-07-01	37940
2002-10-01	38141
2003-01-01	38944
2003-04-01	40451
2003-07-01	40814
2003-10-01	41154
2004-01-01	42137
2004-04-01	42606
2004-07-01	44457
2004-10-01	45192
2005-01-01	46663
2005-04-01	46476
2005-07-01	45995
2005-10-01	42181
2006-01-01	42788
2006-04-01	44135
2006-07-01	43665
2006-10-01	44911
2007-01-01	44289
2007-04-01	46379
2007-07-01	46733
2007-10-01	46564
2008-01-01	47038
2008-04-01	47454
2008-07-01	48607
2008-10-01	49315
2009-01-01	46198
2009-04-01	47872
2009-07-01	48533
2009-10-01	48920
2010-01-01	51873
2010-04-01	52769
2010-07-01	57803
2010-10-01	63348
2011-01-01	64626
2011-04-01	80148
2011-07-01	84314
2011-10-01	89615
2012-01-01	102942
2012-04-01	108905
2012-07-01	117156
2012-10-01	121055
2013-01-01	130709
2013-04-01	145814
2013-07-01	150175
2013-10-01	159884
2014-01-01	171034
2014-04-01	186961
2014-07-01	200120
2014-10-01	200554
2015-01-01	208091
2015-04-01	211611
2015-07-01	202908
2015-10-01	220915
2016-01-01	215627
2016-04-01	212684
2016-07-01	224751
2016-10-01	228929
2017-01-01	245269
2017-04-01	262494
2017-07-01	273659
2017-10-01	294394
2018-01-01	301068
2018-04-01	315402