Year	current US$
2000	9.83387169
2001	4.09224667
2002	3.09717866
2003	4.2689154
2004	5.87357424
2005	6.16445446
2006	7.38118605
2007	7.65158642
2008	7.89785355
2009	5.9863145
2010	4.64592534
2011	4.76755419
2012	5.48776372
2013	6.25670204
2014	7.2749092
2015	7.16129143
2016	7.42493227
2017	7.52313003
2018	7.43936765
2019	7.64462581
2020	8.44159415
2021	8.73400875