Year	constant 2015 US$
1991	4062.1621037072714
1992	3984.6510035629626
1993	3994.207942016256
1994	4182.739685869761
1995	4293.519373527358
1996	4260.624296171316
1997	4299.306448344669
1998	4298.717637855152
1999	4342.778813430724
2000	4127.892671367524
2001	3741.116718630005
2002	3999.092196607711
2003	3821.239005285732
2004	4066.734342173014
2005	3970.367237894536
2006	4183.321944970534
2007	4575.659678782868
2008	4513.652626927865
2009	4122.0976000025685
2010	4036.646191638019
2011	4081.8661210145538
2012	4160.878628674681
2013	4562.5448498497735
2014	4779.7815165421425
2015	4925.552285175889
2016	5044.33394301891
2017	5055.32701316924
2018	5059.03911201314
2019	5481.625021269541
2020	5737.22887657129
2021	5932.502553352577
2022	6212.154556236541