Year	constant 2015 US$
1989	31603.626381921433
1990	30182.667518622882
1991	28326.890967836476
1992	27356.30307958658
1993	26526.729593166157
1994	26809.797381920038
1995	31374.800816127597
1996	34204.71610359309
1997	28225.46178259398
1998	28878.801541952966
1999	30892.873768201567
2000	31668.22611586502
2001	31839.741495064543
2002	32330.110098357873
2003	31641.223483989208
2004	31573.81218559303
2005	32087.010764993753
2006	32368.57359580594
2007	32342.89542730237
2008	31663.360301606244
2009	29672.15753988225
2010	29480.28000457653
2011	29307.177156764017
2012	29808.587149979412
2013	28616.755631328935
2014	28549.756935091216
2015	28462.35138032631
2016	27787.90129141011
2017	28425.785884727753
2018	28325.06836472596
2019	28289.746552349472
2020	22030.400844923657
2021	25587.46795693738
2022	28016.734352690004