Year U.S. Dollars 2009-01-01 20214400000 2010-01-01 22583200000 2011-01-01 29233300000 2012-01-01 35164300000 2013-01-01 39197500000 2014-01-01 43524200000 2015-01-01 35799600000 2016-01-01 36180000000 2017-01-01 37926300000 2018-01-01 42353500000 2019-01-01 46401000000