Year	current US$
2000	14.40263557
2001	13.59540498
2002	12.71010396
2003	19.93518091
2004	25.93679879
2005	28.96695295
2006	29.6444259
2007	30.80087235
2008	28.2245237
2009	29.42693932
2010	36.24907223
2011	38.72238872
2012	36.13029049
2013	32.28327854
2014	30.07433557
2015	26.70462844
2016	24.11317472
2017	28.0337097
2018	29.50183322
2019	27.42960165
2020	24.72793361
2021	29.18532