Year	current US$
2008	1653.0415371390898
2009	1325.2750772157954
2010	1503.1338890108184
2011	1455.3584071886235
2012	1114.9237226019134
2013	1659.140787284778
2014	1245.1493110722627
2015	1071.7777647554512