Year	current US$
2000	3.2331953403405
2001	3.468992180716369
2002	3.520486008071391
2003	4.166042611393859
2004	4.765766809986534
2005	5.342426443944293
2006	6.1234220676876365
2007	7.48985157595733
2008	8.960895397707061
2009	8.971431968361312
2010	8.432988633344497
2011	9.013564838891964
2012	9.817563936468462
2013	10.510332569719553
2014	10.933648648491037
2015	9.723290329973107
2016	10.047068781854804
2017	10.78012956947425
2018	10.140407680789563
2019	10.050556517870383
2020	10.965774084427002
2021	11.496802492826157