Year	constant 2015 US$
1991	459.27744966155853
1992	458.3834764501558
1993	450.21672743408817
1994	419.4352017396512
1995	446.85024842344745
1996	453.77961773880736
1997	437.1099064104723
1998	423.1453825326629
1999	418.83218565723354
2000	360.6505676819674
2001	342.2299796398157
2002	321.91129668238034
2003	317.35960566053836
2004	315.55587745256
2005	310.5207989554114
2006	326.7358118357039
2007	335.4231521274059
2008	344.2308243089065
2009	354.59488394824916
2010	369.4776908875901
2011	385.67995739238904
2012	403.444108159329
2013	414.6077449631494
2014	427.7066644210236
2015	441.1220335858397
2016	444.21575693448045
2017	439.99724601992887
2018	437.97597489821516
2019	444.9596753991007
2020	449.8573937862192
2021	445.61765513833944
2022	442.1774154566864