Year	current US$
2000	54.38904953
2001	56.32826996
2002	63.35457993
2003	77.51076508
2004	90.9294281
2005	96.96191406
2006	110.00260162
2007	131.66958618
2008	153.10005188
2009	165.44444275
2010	168.37710571
2011	179.04853821
2012	172.05938721
2013	179.73484802
2014	188.40020752
2015	162.5098114
2016	161.82783508
2017	166.4662323
2018	175.27603149
2019	177.24557495
2020	193.10235596
2021	221.11485291