Year	current US$
2000	6.9896342
2001	6.57499105
2002	12.14446965
2003	8.42512776
2004	13.05538632
2005	13.10226073
2006	14.99743446
2007	10.9350915
2008	12.09733306
2009	21.02827627
2010	31.67424419
2011	25.12364592
2012	35.00553386
2013	49.23539834
2014	74.90775654
2015	46.82363721
2016	32.00855379
2017	26.78283474
2018	24.25371879
2019	32.11789221
2020	27.68880427
2021	83.10839108