Quarter	Millions of US Dollars
1975-04-01	53
1975-07-01	78
1975-10-01	78
1976-01-01	78
1976-04-01	78
1976-07-01	78
1976-10-01	78
1977-01-01	78
1977-04-01	78
1977-07-01	78
1977-10-01	78
1978-01-01	78
1978-04-01	78
1978-07-01	103
1978-10-01	103
1979-01-01	151
1979-04-01	184
1979-07-01	183
1979-10-01	180
1980-01-01	178
1980-04-01	184
1980-07-01	266
1980-10-01	292
1981-01-01	285
1981-04-01	304
1981-07-01	305
1981-10-01	311
1982-01-01	301
1982-04-01	297
1982-07-01	268
1982-10-01	278
1983-01-01	275
1983-04-01	273
1983-07-01	272
1983-10-01	271
1984-01-01	275
1984-04-01	268
1984-07-01	262
1984-10-01	259
1985-01-01	260
1985-04-01	261
1985-07-01	240
1985-10-01	247
1986-01-01	232
1986-04-01	241
1986-07-01	177
1986-10-01	116
1987-01-01	122
1987-04-01	121
1987-07-01	122
1987-10-01	136
1988-01-01	134
1988-04-01	128
1988-07-01	128
1988-10-01	133
1989-01-01	129
1989-04-01	123
1989-07-01	125
1989-10-01	123
1990-01-01	117
1990-04-01	66
1990-07-01	72
1990-10-01	74
1991-01-01	320
1991-04-01	320
1991-07-01	320
1991-10-01	320
1992-01-01	360
1992-04-01	380
1992-07-01	380
1992-10-01	380
1993-01-01	415
1993-04-01	748
1993-07-01	833
1993-10-01	928
1994-01-01	827
1994-04-01	812
1994-07-01	812
1994-10-01	817
1995-01-01	742
1995-04-01	742
1995-07-01	742
1995-10-01	742
1996-01-01	988
1996-04-01	1328
1996-07-01	1768
1996-10-01	1768
1997-01-01	1852
1997-04-01	1852
1997-07-01	2152
1997-10-01	2802
1998-01-01	2802
1998-04-01	3252
1998-07-01	3252
1998-10-01	3465
1999-01-01	3825
1999-04-01	4625
1999-07-01	4838
1999-10-01	4826
2000-01-01	4916
2000-04-01	4916
2000-07-01	5297
2000-10-01	5313
2001-01-01	5299
2001-04-01	5508
2001-07-01	6349
2001-10-01	6989
2002-01-01	6986
2002-04-01	7924
2002-07-01	8179
2002-10-01	9026
2003-01-01	9975
2003-04-01	9900
2003-07-01	9921
2003-10-01	9948
2004-01-01	10372
2004-04-01	10368
2004-07-01	10124
2004-10-01	10660
2005-01-01	10641
2005-04-01	10764
2005-07-01	10707
2005-10-01	10707
2006-01-01	10090
2006-04-01	10490
2006-07-01	10290
2006-10-01	10790
2007-01-01	10924
2007-04-01	11194
2007-07-01	10507
2007-10-01	10322
2008-01-01	9712
2008-04-01	9642
2008-07-01	10031
2008-10-01	10024
2009-01-01	10614
2009-04-01	9780
2009-07-01	10137
2009-10-01	11190
2010-01-01	11685
2010-04-01	12064
2010-07-01	14322
2010-10-01	15843
2011-01-01	17477
2011-04-01	17723
2011-07-01	18540
2011-10-01	20162
2012-01-01	20286
2012-04-01	20744
2012-07-01	22962
2012-10-01	25861
2013-01-01	27525
2013-04-01	29721
2013-07-01	31851
2013-10-01	35557
2014-01-01	36203
2014-04-01	36696
2014-07-01	41866
2014-10-01	45979
2015-01-01	46912
2015-04-01	50870
2015-07-01	52941
2015-10-01	52854
2016-01-01	55744
2016-04-01	55368
2016-07-01	56332
2016-10-01	56147
2017-01-01	56860
2017-04-01	62154
2017-07-01	69005
2017-10-01	69647
2018-01-01	72426
2018-04-01	71827