Year	current US$
2000	22.92838191
2001	22.82633611
2002	25.7912848
2003	23.53147404
2004	27.07313079
2005	28.25529591
2006	32.64759006
2007	38.62767717
2008	43.80010368
2009	42.35288095
2010	43.23394566
2011	46.35609032
2012	49.22027917
2013	50.58325194
2014	53.92953121
2015	57.08043367
2016	58.60598845
2017	59.95391076
2018	55.85550047
2019	53.80799192
2020	52.02243795
2021	61.04131372