Quarter Millions of US Dollars 1972-04-01 32 1972-07-01 31 1972-10-01 51 1973-01-01 55 1973-04-01 61 1973-07-01 61 1973-10-01 87 1974-01-01 89 1974-04-01 89 1974-07-01 88 1974-10-01 91 1975-01-01 93 1975-04-01 104 1975-07-01 100 1975-10-01 119 1976-01-01 121 1976-04-01 145 1976-07-01 209 1976-10-01 282 1977-01-01 344 1977-04-01 349 1977-07-01 382 1977-10-01 465 1978-01-01 506 1978-04-01 513 1978-07-01 540 1978-10-01 543 1979-01-01 552 1979-04-01 550 1979-07-01 559 1979-10-01 551 1980-01-01 524 1980-04-01 558 1980-07-01 557 1980-10-01 548 1981-01-01 607 1981-04-01 581 1981-07-01 552 1981-10-01 541 1982-01-01 518 1982-04-01 506 1982-07-01 558 1982-10-01 556 1983-01-01 486 1983-04-01 460 1983-07-01 462 1983-10-01 521 1984-01-01 525 1984-04-01 517 1984-07-01 497 1984-10-01 494 1985-01-01 498 1985-04-01 474 1985-07-01 493 1985-10-01 545 1986-01-01 474 1986-04-01 487 1986-07-01 498 1986-10-01 648 1987-01-01 707 1987-04-01 781 1987-07-01 781 1987-10-01 874 1988-01-01 968 1988-04-01 941 1988-07-01 939 1988-10-01 876 1989-01-01 849 1989-04-01 849 1989-07-01 781 1989-10-01 572 1990-01-01 640 1990-04-01 600 1990-07-01 600 1990-10-01 750 1991-01-01 784 1991-04-01 804 1991-07-01 856 1991-10-01 817 1992-01-01 855 1992-04-01 806 1992-07-01 807 1992-10-01 730 1993-01-01 731 1993-04-01 656 1993-07-01 796 1993-10-01 971 1994-01-01 1220 1994-04-01 1294 1994-07-01 1347 1994-10-01 1400 1995-01-01 1323 1995-04-01 1353 1995-07-01 1362 1995-10-01 1242 1996-01-01 1220 1996-04-01 1826 1996-07-01 1966 1996-10-01 3260 1997-01-01 3787 1997-04-01 4477 1997-07-01 5188 1997-10-01 5051 1998-01-01 4931 1998-04-01 7408 1998-07-01 7523 1998-10-01 7585 1999-01-01 8413 1999-04-01 8175 1999-07-01 9404 1999-10-01 10316 2000-01-01 10565 2000-04-01 13652 2000-07-01 14028 2000-10-01 14560 2001-01-01 15969 2001-04-01 16062 2001-07-01 18167 2001-10-01 20876 2002-01-01 21118 2002-04-01 19999 2002-07-01 19761 2002-10-01 20099 2003-01-01 20445 2003-04-01 21832 2003-07-01 23318 2003-10-01 27082 2004-01-01 28301 2004-04-01 30114 2004-07-01 31200 2004-10-01 34910 2005-01-01 35333 2005-04-01 35092 2005-07-01 37572 2005-10-01 38183 2006-01-01 37473 2006-04-01 41169 2006-07-01 42437 2006-10-01 42906 2007-01-01 42511 2007-04-01 45932 2007-07-01 47063 2007-10-01 47767 2008-01-01 49119 2008-04-01 50690 2008-07-01 51346 2008-10-01 49480 2009-01-01 47022 2009-04-01 45115 2009-07-01 47291 2009-10-01 49659 2010-01-01 51063 2010-04-01 49493 2010-07-01 54241 2010-10-01 54835 2011-01-01 58170 2011-04-01 62017 2011-07-01 62467 2011-10-01 64034 2012-01-01 71102 2012-04-01 68424 2012-07-01 75169 2012-10-01 79201 2013-01-01 83194 2013-04-01 86756 2013-07-01 93381 2013-10-01 95525 2014-01-01 96065 2014-04-01 99986 2014-07-01 103261 2014-10-01 95888 2015-01-01 91508 2015-04-01 95269 2015-07-01 89029 2015-10-01 87640 2016-01-01 90833 2016-04-01 87075 2016-07-01 89180 2016-10-01 84497 2017-01-01 88807 2017-04-01 91575 2017-07-01 101283 2017-10-01 102456 2018-01-01 115584 2018-04-01 124039