Year	current US$
2000	304.18500068
2001	339.77447985
2002	438.38212793
2003	560.46039781
2004	653.80273929
2005	726.68378866
2006	805.5387203
2007	930.24390895
2008	1173.89027622
2009	1195.37963261
2010	1281.23325893
2011	1393.71739579
2012	1277.39978362
2013	1274.33149255
2014	1270.06266703
2015	1103.96483111
2016	1161.87396575
2017	1281.97429012
2018	1482.13329662
2019	1526.63381613
2020	1853.10118673
2021	2153.11890338