Year	current US$
2000	2.52485553
2001	6.76976519
2002	3.1973289
2003	4.28504436
2004	8.00807233
2005	8.879088
2006	15.72450181
2007	13.48187073
2008	8.59718982
2009	5.41516703
2010	7.92983999
2011	7.54616648
2012	7.28474272
2013	8.33250472
2014	7.51021366
2015	4.89779694
2016	4.62698534
2017	11.54685678
2018	6.15463547
2019	8.03187153
2020	6.86770465
2021	26.55380644