Year	constant 2010 US$
1991	25293.692113503
1992	25092.6940126472
1993	24652.5277049097
1994	24666.2862979455
1995	23255.4327071469
1996	22935.3501498013
1997	23563.2755335114
1998	23328.2971148346
1999	24362.9836729405
2000	24642.9917639046
2001	24011.9546945599
2002	23287.3240719623
2003	22936.5777596019
2004	22794.1508406899
2005	22747.8010311468
2006	22825.2160281761
2007	22820.6458155463
2008	22747.1587166851
2009	21277.9765138172
2010	22155.1165639158
2011	22522.0238662072
2012	22612.5458091809
2013	22842.7933500604
2014	23481.5570450925
2015	23893.0772784745
2016	24427.8686746859
2017	24828.5261117175
2018	24994.4546515541