Year	constant 2015 US$
1994	16710.67859006468
1995	15687.755457080282
1996	17228.70168026917
1997	17234.14380658945
1998	17871.573205425208
1999	18229.523217089914
2000	20719.65321916459
2001	20023.06978738964
2002	22403.546987898604
2003	20512.390686775063
2004	18436.876093107894
2005	18980.21270029381
2006	19352.46457096982
2007	20650.423002206368
2008	22385.144965349962
2009	21202.521531362225
2010	20823.055184888883
2011	22486.409271188368
2012	21995.67822492709
2013	22455.024106462482
2014	21404.589705763847
2015	20591.081034424802
2016	19339.928564720172
2017	19599.06735137036
2018	17536.036481151797
2019	18828.59529059473
2020	18942.30797995651
2021	19995.755255649405
2022	22535.724847493235