Year	current US$
2000	19.86673944
2001	17.69901415
2002	18.964946
2003	22.23591217
2004	25.99797209
2005	24.30169821
2006	23.99272141
2007	23.51846688
2008	33.84475185
2009	38.67988974
2010	39.60290309
2011	46.39140878
2012	51.49725087
2013	65.62145756
2014	75.13942076
2015	42.49589188
2016	43.29347866
2017	38.674727
2018	35.06594258
2019	36.63097277
2020	36.64176565
2021	41.54693434