Quarter	Millions of US Dollars
1978-07-01	105
1978-10-01	107
1979-01-01	138
1979-04-01	137
1979-07-01	166
1979-10-01	164
1980-01-01	152
1980-04-01	168
1980-07-01	212
1980-10-01	204
1981-01-01	192
1981-04-01	220
1981-07-01	221
1981-10-01	232
1982-01-01	214
1982-04-01	406
1982-07-01	437
1982-10-01	535
1983-01-01	566
1983-04-01	560
1983-07-01	852
1983-10-01	850
1984-01-01	860
1984-04-01	842
1984-07-01	793
1984-10-01	785
1985-01-01	787
1985-04-01	789
1985-07-01	791
1985-10-01	767
1986-01-01	1094
1986-04-01	1118
1986-07-01	1138
1986-10-01	1133
1987-01-01	1163
1987-04-01	1160
1987-07-01	1161
1987-10-01	1229
1988-01-01	1218
1988-04-01	1187
1988-07-01	1108
1988-10-01	1299
1989-01-01	1234
1989-04-01	1210
1989-07-01	1089
1989-10-01	1109
1990-01-01	1102
1990-04-01	1108
1990-07-01	1130
1990-10-01	1061
1991-01-01	1025
1991-04-01	949
1991-07-01	961
1991-10-01	984
1992-01-01	964
1992-04-01	805
1992-07-01	826
1992-10-01	791
1993-01-01	736
1993-04-01	728
1993-07-01	735
1993-10-01	300
1994-01-01	300
1994-04-01	300
1994-07-01	300
1994-10-01	300
1995-01-01	300
1995-04-01	300
1995-07-01	300
1995-10-01	300
1996-01-01	300
1996-04-01	300
1996-07-01	700
1996-10-01	700
1997-01-01	700
1997-04-01	700
1997-07-01	700
1997-10-01	700
1998-01-01	700
1998-04-01	700
1998-07-01	700
1998-10-01	700
1999-01-01	700
1999-04-01	700
1999-07-01	700
1999-10-01	700
2000-01-01	700
2000-04-01	700
2000-07-01	700
2000-10-01	700
2001-01-01	400
2001-04-01	400
2001-07-01	400
2001-10-01	400
2002-01-01	400
2002-04-01	400
2002-07-01	400
2002-10-01	400
2003-01-01	400
2003-04-01	400
2003-07-01	400
2003-10-01	400
2004-01-01	1400
2004-04-01	1400
2004-07-01	1400
2004-10-01	1400
2005-01-01	1400
2005-04-01	2400
2005-07-01	2400
2005-10-01	3900
2006-01-01	5900
2006-04-01	5900
2006-07-01	5500
2006-10-01	5500
2007-01-01	7000
2007-04-01	7000
2007-07-01	7000
2007-10-01	7000
2008-01-01	9000
2008-04-01	11200
2008-07-01	11200
2008-10-01	11200
2009-01-01	16200
2009-04-01	16850
2009-07-01	17241
2009-10-01	17229
2010-01-01	19225
2010-04-01	19245
2010-07-01	19270
2010-10-01	20018
2011-01-01	19998
2011-04-01	22531
2011-07-01	22586
2011-10-01	22577
2012-01-01	26008
2012-04-01	28544
2012-07-01	28574
2012-10-01	29150
2013-01-01	28992
2013-04-01	31917
2013-07-01	32938
2013-10-01	32827
2014-01-01	35551
2014-04-01	33929
2014-07-01	36369
2014-10-01	36234
2015-01-01	41972
2015-04-01	41038
2015-07-01	44566
2015-10-01	47924
2016-01-01	47410
2016-04-01	56525
2016-07-01	55295
2016-10-01	57678
2017-01-01	56998
2017-04-01	58701
2017-07-01	66551
2017-10-01	69792
2018-01-01	68593
2018-04-01	70669