Year	current US$
2000	9.47011846
2001	9.61533868
2002	10.76470629
2003	13.57961584
2004	15.80712457
2005	16.64767303
2006	18.17570297
2007	21.43655143
2008	25.14293375
2009	25.44118631
2010	23.88107337
2011	25.05569025
2012	22.0494082
2013	23.10489023
2014	24.18358454
2015	20.50084893
2016	28.28254629
2017	28.65014738
2018	28.22403141
2019	28.95002842
2020	37.03744416
2021	35.60015319