Year	current US$
2000	4.6126643
2001	4.76209295
2002	4.63881333
2003	5.47901923
2004	6.29692733
2005	7.86513404
2006	14.86274993
2007	15.26483285
2008	9.28157131
2009	11.67984157
2010	14.54437908
2011	16.81243733
2012	20.12340148
2013	20.89466222
2014	17.20023779
2015	12.45418618
2016	13.20526958
2017	15.15634418
2018	16.67081837
2019	14.55138835
2020	13.04712842
2021	17.2082819