Quarter	Millions of US Dollars
1975-04-01	42
1975-07-01	38
1975-10-01	38
1976-01-01	39
1976-04-01	39
1976-07-01	41
1976-10-01	92
1977-01-01	92
1977-04-01	93
1977-07-01	93
1977-10-01	97
1978-01-01	124
1978-04-01	223
1978-07-01	227
1978-10-01	266
1979-01-01	265
1979-04-01	265
1979-07-01	269
1979-10-01	269
1980-01-01	263
1980-04-01	268
1980-07-01	267
1980-10-01	287
1981-01-01	284
1981-04-01	278
1981-07-01	279
1981-10-01	431
1982-01-01	467
1982-04-01	422
1982-07-01	421
1982-10-01	671
1983-01-01	678
1983-04-01	677
1983-07-01	677
1983-10-01	676
1984-01-01	677
1984-04-01	684
1984-07-01	680
1984-10-01	780
1985-01-01	814
1985-04-01	916
1985-07-01	948
1985-10-01	851
1986-01-01	1037
1986-04-01	1086
1986-07-01	1033
1986-10-01	659
1987-01-01	696
1987-04-01	695
1987-07-01	701
1987-10-01	882
1988-01-01	791
1988-04-01	749
1988-07-01	730
1988-10-01	827
1989-01-01	785
1989-04-01	761
1989-07-01	981
1989-10-01	995
1990-01-01	984
1990-04-01	1008
1990-07-01	1062
1990-10-01	1073
1991-01-01	1019
1991-04-01	1003
1991-07-01	1037
1991-10-01	1039
1992-01-01	1004
1992-04-01	870
1992-07-01	911
1992-10-01	775
1993-01-01	678
1993-04-01	628
1993-07-01	689
1993-10-01	612
1994-01-01	646
1994-04-01	625
1994-07-01	841
1994-10-01	786
1995-01-01	792
1995-04-01	1270
1995-07-01	1231
1995-10-01	1343
1996-01-01	1504
1996-04-01	1459
1996-07-01	1218
1996-10-01	1052
1997-01-01	1507
1997-04-01	1581
1997-07-01	1597
1997-10-01	1419
1998-01-01	1692
1998-04-01	1599
1998-07-01	1628
1998-10-01	1698
1999-01-01	1804
1999-04-01	1753
1999-07-01	1784
1999-10-01	1763
2000-01-01	1738
2000-04-01	1715
2000-07-01	2173
2000-10-01	1899
2001-01-01	1578
2001-04-01	1966
2001-07-01	1954
2001-10-01	1830
2002-01-01	1985
2002-04-01	2437
2002-07-01	2416
2002-10-01	2290
2003-01-01	2230
2003-04-01	2258
2003-07-01	2287
2003-10-01	2479
2004-01-01	2486
2004-04-01	2400
2004-07-01	2368
2004-10-01	2723
2005-01-01	2564
2005-04-01	2459
2005-07-01	2553
2005-10-01	2451
2006-01-01	2136
2006-04-01	2705
2006-07-01	2710
2006-10-01	2852
2007-01-01	2954
2007-04-01	2634
2007-07-01	2356
2007-10-01	3749
2008-01-01	3823
2008-04-01	3475
2008-07-01	2618
2008-10-01	2524
2009-01-01	2319
2009-04-01	2552
2009-07-01	2532
2009-10-01	2692
2010-01-01	2607
2010-04-01	3159
2010-07-01	3513
2010-10-01	6923
2011-01-01	9310
2011-04-01	9095
2011-07-01	11704
2011-10-01	12788
2012-01-01	14295
2012-04-01	14342
2012-07-01	16069
2012-10-01	16210
2013-01-01	16038
2013-04-01	16147
2013-07-01	16467
2013-10-01	16316
2014-01-01	12391
2014-04-01	12740
2014-07-01	12923
2014-10-01	12979
2015-01-01	12906
2015-04-01	13057
2015-07-01	13242
2015-10-01	13211
2016-01-01	13152
2016-04-01	16173
2016-07-01	13941
2016-10-01	10959
2017-01-01	9824
2017-04-01	9939
2017-07-01	10037
2017-10-01	10692
2018-01-01	10956
2018-04-01	10742