Quarter US dollars 2004-12-31 4590 2005-03-31 5348 2005-06-30 5501 2005-09-30 6177 2005-12-31 5164 2006-03-31 5455 2006-06-30 5337 2006-09-30 5672 2006-12-31 6556 2007-03-31 6784 2007-06-30 8214 2007-09-30 11768 2007-12-31 12443 2008-03-31 13837 2008-06-30 14438 2008-09-30 13893 2008-12-31 15190 2009-03-31 14342 2009-06-30 13911 2009-09-30 15911 2009-12-31 15822 2010-03-31 15087 2010-06-30 18022 2010-09-30 21485 2010-12-31 22612 2011-03-31 21647 2011-06-30 24911 2011-09-30 25765 2011-12-31 26630 2012-03-31 27324 2012-06-30 29968 2012-09-30 28792 2012-12-31 31489 2013-03-31 35970 2013-06-30 32720 2013-09-30 35214 2013-12-31 35477 2014-03-31 37237 2014-06-30 37579 2014-09-30 38500 2014-12-31 39171 2015-03-31 37077 2015-06-30 37190 2015-09-30 32854 2015-12-31 34392 2016-03-31 31310 2016-06-30 29786 2016-09-30 26933 2016-12-31 26987 2017-03-31 28872 2017-06-30 21150 2017-09-30 20100 2017-12-31 20114 2018-03-31 19723 2018-06-30 19134 2018-09-30 20667 2018-12-31 23468 2019-03-31 24968 2019-06-30 23899 2019-09-30 25631 2019-12-31 24763 2020-03-31 25917 2020-06-30 26482 2020-09-30 25503 2020-12-31 25670 2021-03-31 30521 2021-06-30 31547 2021-09-30 32985 2021-12-31 30240 2022-03-31 31197 2022-06-30 28875 2022-09-30 28446 2022-12-31 26706 2023-03-31 25476 2023-06-30 25261 2023-09-30 24206