Quarter US dollars 2004-12-31 4 2005-03-31 4 2005-06-30 4 2005-09-30 0 2005-12-31 0 2006-03-31 0 2006-06-30 0 2006-09-30 0 2006-12-31 0 2007-03-31 0 2007-06-30 0 2007-09-30 0 2007-12-31 0 2008-03-31 0 2008-06-30 0 2008-09-30 12 2008-12-31 14 2009-03-31 6 2009-06-30 15 2009-09-30 8 2009-12-31 16 2010-03-31 9 2010-06-30 18 2010-09-30 11 2010-12-31 19 2011-03-31 11 2011-06-30 18 2011-09-30 17 2011-12-31 23 2012-03-31 14 2012-06-30 25 2012-09-30 2 2012-12-31 2 2013-03-31 2 2013-06-30 3 2013-09-30 2 2013-12-31 2 2014-03-31 0 2014-06-30 0 2014-09-30 0 2014-12-31 0 2015-03-31 0 2015-06-30 0 2015-09-30 0 2015-12-31 0 2016-03-31 0 2016-06-30 0 2016-09-30 0 2016-12-31 0 2017-03-31 0 2017-06-30 561 2017-09-30 531 2017-12-31 513 2018-03-31 417 2018-06-30 434 2018-09-30 522 2018-12-31 366 2019-03-31 318 2019-06-30 299 2019-09-30 257 2019-12-31 244 2020-03-31 172 2020-06-30 125 2020-09-30 125 2020-12-31 97 2021-03-31 70 2021-06-30 62 2021-09-30 47 2021-12-31 36 2022-03-31 29 2022-06-30 0 2022-09-30 0 2022-12-31 0 2023-03-31 0 2023-06-30 0 2023-09-30 0