Year	current US$
2002	17.00758553
2003	17.81492424
2004	21.42946434
2005	25.10707283
2006	28.91982269
2007	32.71720505
2008	39.96989822
2009	43.26076889
2010	46.57987976
2011	52.36304855
2012	52.61354065
2013	56.30554199
2014	60.18957901
2015	60.05854034
2016	61.48645782
2017	66.90921783
2018	71.33430481
2019	74.23410797
2020	80.28805542
2021	81.31976318