Year	current US$
2000	9.737062242135446
2001	9.742382460607883
2002	10.503819215222132
2003	15.550254879878795
2004	16.734877391584003
2005	18.913288933996636
2006	22.594156663491276
2007	25.626512682090084
2008	29.050224338849272
2009	26.2438004190668
2010	28.302971243052756
2011	29.955811801267327
2012	33.7644033143754
2013	37.24642095674057
2014	38.16890635388451
2015	36.096271757194444
2016	31.982647061697545
2017	31.708024596425986
2018	29.53113587068685
2019	29.61649363507547
2020	30.325017266465103
2021	32.75978603445174