Year	current US$
2000	2.61259299
2001	1.83567617
2002	6.99364784
2003	13.8883357
2004	20.0679521
2005	21.02730745
2006	20.97052546
2007	24.81929984
2008	12.88069468
2009	15.25574948
2010	20.46905836
2011	39.46005276
2012	13.21751678
2013	57.4993199
2014	38.69596944
2015	39.11490937
2016	48.12985706
2017	24.41149866
2018	17.35314484
2019	27.79580951
2020	31.20024137
2021	34.04979983