Year	current US$
2000	12.53723475
2001	12.77087241
2002	12.39296958
2003	14.29999233
2004	15.0352676
2005	17.06082904
2006	19.196555
2007	22.91084587
2008	24.48115587
2009	23.75518477
2010	24.8881458
2011	24.48326024
2012	28.01254887
2013	29.64782794
2014	31.16182393
2015	29.73403209
2016	30.4372467
2017	24.03198108
2018	26.28071911
2019	30.56358205
2020	28.96208483
2021	31.08939377