Year	constant 2015 US$
1997	61622.77731217993
1998	62649.083626390835
1999	63821.43859433145
2000	65266.91742373308
2001	65651.62090760104
2002	66501.49017981463
2003	66069.36297233374
2004	67045.98718809179
2005	68144.12654783943
2006	69020.0766986338
2007	68876.86693337998
2008	68677.06953734442
2009	68351.53596726264
2010	68855.4037132976
2011	69903.45148228588
2012	70458.94672111803
2013	70920.90549340103
2014	72272.93251381075
2015	72568.4246437235
2016	73178.14172084176
2017	73481.46505398302
2018	74333.91675495505
2019	74339.73776012722
2020	75077.17936645582
2021	75474.10442813831
2022	74971.32443569932
