Quarter	Millions of US Dollars
1989-10-01	15254
1990-01-01	15896
1990-04-01	16409
1990-07-01	17208
1990-10-01	18185
1991-01-01	16004
1991-04-01	15580
1991-07-01	16694
1991-10-01	16044
1992-01-01	14149
1992-04-01	15194
1992-07-01	14211
1992-10-01	12483
1993-01-01	10952
1993-04-01	12180
1993-07-01	11890
1993-10-01	11246
1994-01-01	11222
1994-04-01	10900
1994-07-01	11382
1994-10-01	10957
1995-01-01	11274
1995-04-01	11365
1995-07-01	10798
1995-10-01	10208
1996-01-01	9791
1996-04-01	9549
1996-07-01	9916
1996-10-01	9274
1997-01-01	9237
1997-04-01	8655
1997-07-01	7835
1997-10-01	8760
1998-01-01	9129
1998-04-01	8792
1998-07-01	9361
1998-10-01	9119
1999-01-01	10287
1999-04-01	10494
1999-07-01	9897
1999-10-01	9630
2000-01-01	10605
2000-04-01	11549
2000-07-01	11387
2000-10-01	12673
2001-01-01	13082
2001-04-01	14084
2001-07-01	15183
2001-10-01	14280
2002-01-01	15052
2002-04-01	17369
2002-07-01	16924
2002-10-01	17170
2003-01-01	19417
2003-04-01	20474
2003-07-01	19895
2003-10-01	21865
2004-01-01	21781
2004-04-01	22110
2004-07-01	21338
2004-10-01	22892
2005-01-01	22801
2005-04-01	22940
2005-07-01	22828
2005-10-01	22094
2006-01-01	23516
2006-04-01	27471
2006-07-01	26606
2006-10-01	26934
2007-01-01	28799
2007-04-01	30298
2007-07-01	31541
2007-10-01	30371
2008-01-01	33465
2008-04-01	33592
2008-07-01	29449
2008-10-01	25741
2009-01-01	28432
2009-04-01	32936
2009-07-01	34992
2009-10-01	33513
2010-01-01	30299
2010-04-01	27715
2010-07-01	32955
2010-10-01	32137
2011-01-01	35708
2011-04-01	37122
2011-07-01	35181
2011-10-01	32624
2012-01-01	36420
2012-04-01	36101
2012-07-01	39871
2012-10-01	42548
2013-01-01	43434
2013-04-01	45683
2013-07-01	49945
2013-10-01	50661
2014-01-01	50299
2014-04-01	47258
2014-07-01	43598
2014-10-01	39746
2015-01-01	37163
2015-04-01	38515
2015-07-01	36834
2015-10-01	34528
2016-01-01	37423
2016-04-01	34578
2016-07-01	33972
2016-10-01	31315
2017-01-01	32069
2017-04-01	36291
2017-07-01	38103
2017-10-01	37436
2018-01-01	38782