Year	current US$
2000	1.1061071289539244
2001	1.187042203345611
2002	1.6395236548582908
2003	1.460365369452341
2004	3.8262463024891753
2005	1.9032825351696023
2006	1.7929287846801367
2007	1.7463860824148905
2008	2.2988513362069116
2009	2.5240444310923866
2010	3.2556220121907207
2011	4.622679131467353
2012	3.8119224556895372
2013	2.919656934394527
2014	4.089943029408608
2015	3.2774523451026147
2016	2.433965470446954
2017	2.2890158131734037
2018	2.0252949575564965
2019	1.9105149746663312
2020	1.6066249312424914
2021	3.083305218936426