Year current US$ 1997 313700000 1998 225000000 1999 16149999.999999998 2000 18500000 2001 483000000 2006 40500000 2007 25400000 2008 177400000 2009 88530000 2010 137130000 2011 324507000 2012 1527800000 2013 40300000 2014 516500000 2015 300000000 2016 170000000 2017 438000000 2018 269000000 2019 35710000 2020 2087000000 2022 613000000