Year	current US$
2000	321.80123901
2001	366.98071289
2002	388.02792358
2003	414.04000854
2004	448.06021118
2005	485.67388916
2006	516.06396484
2007	560.4942627
2008	576.71539307
2009	496.8142395
2010	539.26550293
2011	570.73046875
2012	587.82843018
2013	631.21350098
2014	615.10314941
2015	558.1651001
2016	492.87399292
2017	514.88970947
2018	530.64782715
2019	552.70422363
2020	538.51751709
2021	610.64532471