Year	current US$
2000	12.25793076
2001	15.08091736
2002	16.92565536
2003	20.26038742
2004	23.29498863
2005	27.53238869
2006	35.36390686
2007	35.99416351
2008	36.01263428
2009	33.38547516
2010	36.89682007
2011	37.43364334
2012	41.63511276
2013	43.09357452
2014	39.47782898
2015	32.90985107
2016	36.26340103
2017	38.65550995
2018	40.83135605
2019	39.5618248
2020	31.39298439
2021	37.15989685