Year	current US$
2000	9.61407046
2001	9.44528501
2002	10.53438825
2003	12.59128956
2004	13.29263526
2005	13.66553418
2006	13.83680881
2007	16.9852321
2008	20.2748859
2009	20.91378731
2010	21.41375798
2011	24.00421851
2012	23.45638955
2013	25.76949767
2014	27.82037774
2015	24.48207713
2016	36.23721711
2017	36.40886967
2018	39.68829834
2019	38.02323302
2020	38.01141851
2021	40.00884572