Year	current US$
2000	460.9066279
2001	450.65609138
2002	494.93375715
2003	642.16978385
2004	781.67111849
2005	848.84764763
2006	904.98657306
2007	1033.71963501
2008	1136.41375021
2009	1082.79896327
2010	1375.35566338
2011	1580.08907577
2012	1746.53132215
2013	1885.7096195
2014	1832.27034779
2015	1542.15739141
2016	1575.9916093
2017	1671.10014282
2018	1670.9517264
2019	1456.42130588
2020	1568.29761301
2021	1690.50861546