Year	current US$
2000	9.49412655
2001	8.98312655
2002	7.7500969
2003	6.35949011
2004	7.98451419
2005	8.292725
2006	13.09752858
2007	13.05233576
2008	14.42176639
2009	14.47833983
2010	25.61874645
2011	49.68805041
2012	45.43221339
2013	28.62856134
2014	35.6362135
2015	34.72121907
2016	29.5754452
2017	18.19073622
2018	25.34270736
2019	20.74214706
2020	13.50187878
2021	20.26433926