Quarter	Millions of US Dollars
1997-10-01	1186036
1998-01-01	1178579
1998-04-01	1092152
1998-07-01	1141328
1998-10-01	1294146
1999-01-01	1287892
1999-04-01	1258721
1999-07-01	1447137
1999-10-01	1488815
2000-01-01	1467948
2000-04-01	1390561
2000-07-01	1343612
2000-10-01	1235351
2001-01-01	1160729
2001-04-01	1250849
2001-07-01	1389387
2001-10-01	1339610
2002-01-01	1393823
2002-04-01	1609928
2002-07-01	1624068
2002-10-01	1741589
2003-01-01	1849655
2003-04-01	1842936
2003-07-01	2014166
2003-10-01	2107217
2004-01-01	2235030
2004-04-01	2139130
2004-07-01	2193168
2004-10-01	2450964
2005-01-01	2458542
2005-04-01	2402302
2005-07-01	2355662
2005-10-01	2533971
2006-01-01	2574819
2006-04-01	2580744
2006-07-01	2532791
2006-10-01	2496967
2007-01-01	2530859
2007-04-01	2408233
2007-07-01	2562205
2007-10-01	2640938
2008-01-01	2973541
2008-04-01	2722146
2008-07-01	2714647
2008-10-01	3153831
2009-01-01	2820650
2009-04-01	2836384
2009-07-01	3054753
2009-10-01	2932812
2010-01-01	2863979
2010-04-01	3052627
2010-07-01	3255792
2010-10-01	3275415
2011-01-01	3128746
2011-04-01	3196354
2011-07-01	3308620
2011-10-01	3274429
2012-01-01	3090065
2012-04-01	3184691
2012-07-01	3225710
2012-10-01	2974938
2013-01-01	2684365
2013-04-01	2501123
2013-07-01	2515172
2013-10-01	2326907
2014-01-01	2367181
2014-04-01	2374038
2014-07-01	2181409
2014-10-01	2008282
2015-01-01	2009901
2015-04-01	1932298
2015-07-01	1970755
2015-10-01	1976094
2016-01-01	2301738
2016-04-01	2423565
2016-07-01	2415005
2016-10-01	2083724
2017-01-01	2212165
2017-04-01	2173506
2017-07-01	2154515
2017-10-01	2160546
2018-01-01	2329363