Year	current US$
2000	24.77188425
2001	25.18616141
2002	27.65791932
2003	26.8982652
2004	28.57823139
2005	29.81212934
2006	34.23365463
2007	40.25650161
2008	45.76412348
2009	44.83408249
2010	45.78234198
2011	48.98814165
2012	52.09251934
2013	53.83293675
2014	57.38813828
2015	60.76054731
2016	61.91520601
2017	63.10769937
2018	58.82006355
2019	56.44849876
2020	54.6331977
2021	63.93881901