Year	current US$
2000	1.87356815
2001	5.99446229
2002	4.83613925
2003	8.35680439
2004	12.11472941
2005	13.25882729
2006	8.51703223
2007	10.09388947
2008	13.64048051
2009	10.85612153
2010	16.37336085
2011	15.47777452
2012	13.20930007
2013	13.82709904
2014	15.69022344
2015	10.06843481
2016	8.73522111
2017	10.71641102
2018	7.00906784
2019	5.8055146
2020	6.88370498
2021	8.55843657