Year	current US$
2000	57.65559193
2001	69.37796222
2002	47.09822799
2003	51.89693783
2004	50.56711965
2005	55.6452147
2006	54.00708333
2007	78.54649105
2008	85.619597
2009	52.61974051
2010	60.14252843
2011	60.74281924
2012	57.00914605
2013	49.63790166
2014	55.20845462
2015	54.18435823
2016	51.34814271
2017	54.32079131
2018	56.01634045
2019	56.3975268
2020	47.84669449
2021	48.71633838