Quarter	Millions of US Dollars
1977-01-01	42
1977-04-01	43
1977-07-01	43
1977-10-01	47
1978-01-01	49
1978-04-01	48
1978-07-01	52
1978-10-01	55
1979-01-01	54
1979-04-01	54
1979-07-01	57
1979-10-01	58
1980-01-01	51
1980-04-01	57
1980-07-01	55
1980-10-01	51
1981-01-01	48
1981-04-01	42
1981-07-01	43
1981-10-01	44
1989-07-01	175
1989-10-01	175
1990-01-01	175
1990-04-01	175
1990-07-01	175
1990-10-01	252
1991-01-01	252
1991-04-01	252
1991-07-01	255
1991-10-01	251
1992-01-01	252
1992-04-01	250
1992-07-01	246
1992-10-01	244
1993-01-01	246
1993-04-01	468
1993-07-01	1965
1993-10-01	1964
1994-01-01	1968
1994-04-01	1979
1994-07-01	1986
1994-10-01	1987
1995-01-01	1990
1995-04-01	1985
1995-07-01	2238
1995-10-01	2258
1996-01-01	2404
1996-04-01	2407
1996-07-01	2684
1996-10-01	2705
1997-01-01	2694
1997-04-01	3200
1997-07-01	3192
1997-10-01	3198
1998-01-01	3203
1998-04-01	3200
1998-07-01	3205
1998-10-01	3061
1999-01-01	3054
1999-04-01	3220
1999-07-01	3227
1999-10-01	3224
2000-01-01	3202
2000-04-01	3194
2000-07-01	3040
2000-10-01	3042
2001-01-01	3035
2001-04-01	3908
2001-07-01	3840
2001-10-01	3838
2002-01-01	3835
2002-04-01	3846
2002-07-01	4079
2002-10-01	4084
2003-01-01	4081
2003-04-01	4088
2003-07-01	4090
2003-10-01	4102
2004-01-01	5781
2004-04-01	5760
2004-07-01	5765
2004-10-01	6907
2005-01-01	7957
2005-04-01	9922
2005-07-01	11022
2005-10-01	13763
2006-01-01	19166
2006-04-01	22336
2006-07-01	24495
2006-10-01	37080
2007-01-01	43633
2007-04-01	45567
2007-07-01	52005
2007-10-01	58767
2008-01-01	59476
2008-04-01	66258
2008-07-01	70674
2008-10-01	66125
2009-01-01	63855
2009-04-01	75131
2009-07-01	82988
2009-10-01	84231
2010-01-01	82490
2010-04-01	80247
2010-07-01	82981
2010-10-01	87883
2011-01-01	93284
2011-04-01	96476
2011-07-01	94764
2011-10-01	101046
2012-01-01	105102
2012-04-01	103400
2012-07-01	106714
2012-10-01	112247
2013-01-01	119614
2013-04-01	120645
2013-07-01	121729
2013-10-01	123624
2014-01-01	123241
2014-04-01	129519
2014-07-01	124991
2014-10-01	123847
2015-01-01	128291
2015-04-01	132719
2015-07-01	133774
2015-10-01	131794
2016-01-01	133727
2016-04-01	146941
2016-07-01	150122
2016-10-01	153454
2017-01-01	151078
2017-04-01	154418
2017-07-01	152063
2017-10-01	165472
2018-01-01	168642
2018-04-01	167507