Year	constant 2010 US$
1991	18185.2842410699
1992	18077.4006657276
1993	17989.4387046998
1994	17696.4729389746
1995	17523.6036238328
1996	17732.6220638483
1997	17851.3931495893
1998	17653.3960931542
1999	17605.6992618571
2000	17715.9773928044
2001	17298.3368361966
2002	17059.7137466169
2003	16806.2127529755
2004	17124.3331280179
2005	17382.5703681286
2006	17627.0679410956
2007	18147.8464601737
2008	18446.9172868652
2009	18114.8708623493
2010	18672.0811843663
2011	19063.9148647442
2012	18999.2827294416
2013	19190.0339324613
2014	19196.4228502184
2015	18878.0991208378
2016	18804.9218875168
2017	18752.7452088386
2018	18756.0829443273