Quarter	Millions of US Dollars
1977-04-01	10
1977-07-01	10
1977-10-01	10
1978-01-01	10
1978-04-01	10
1978-07-01	11
1978-10-01	11
1979-01-01	10
1979-04-01	25
1979-07-01	27
1979-10-01	26
1980-01-01	24
1980-04-01	26
1980-07-01	26
1980-10-01	25
1981-01-01	24
1981-04-01	23
1981-07-01	23
1981-10-01	24
1982-01-01	23
1982-04-01	12
1982-07-01	12
1982-10-01	13
1983-01-01	12
1983-04-01	12
1983-07-01	12
1983-10-01	11
1984-01-01	12
1984-04-01	11
1984-07-01	10
1984-10-01	210
1985-01-01	210
1985-04-01	210
1985-07-01	211
1985-10-01	212
1986-01-01	213
1986-04-01	200
1986-07-01	200
1986-10-01	200
1987-01-01	200
1987-04-01	200
1987-07-01	200
2003-10-01	270
2004-01-01	270
2004-04-01	270
2004-07-01	270
2004-10-01	457
2005-01-01	457
2005-04-01	457
2005-07-01	457
2005-10-01	1157
2006-01-01	1157
2006-04-01	2157
2006-07-01	2601
2006-10-01	4132
2007-01-01	4726
2007-04-01	5402
2007-07-01	8142
2007-10-01	8189
2008-01-01	8206
2008-04-01	9544
2008-07-01	9365
2008-10-01	9293
2009-01-01	9326
2009-04-01	9480
2009-07-01	11412
2009-10-01	11387
2010-01-01	12015
2010-04-01	11904
2010-07-01	12053
2010-10-01	12361
2011-01-01	12411
2011-04-01	11428
2011-07-01	11420
2011-10-01	12276
2012-01-01	12284
2012-04-01	14043
2012-07-01	13065
2012-10-01	13075
2013-01-01	11679
2013-04-01	14128
2013-07-01	14158
2013-10-01	15451
2014-01-01	15461
2014-04-01	17484
2014-07-01	17212
2014-10-01	17202
2015-01-01	15786
2015-04-01	15817
2015-07-01	14286
2015-10-01	13283
2016-01-01	13313
2016-04-01	14077
2016-07-01	14906
2016-10-01	45100
2017-01-01	45614
2017-04-01	55788
2017-07-01	56011
2017-10-01	70505
2018-01-01	71999
2018-04-01	82985