Year	constant 2010 US$
1998	17432.0925435305
1999	17661.7763684264
2000	18034.4159441912
2001	18854.8515832517
2002	19394.1598293934
2003	20093.2614105939
2004	21628.987655345
2005	22831.1780585009
2006	24536.3428689598
2007	26280.8476832173
2008	27722.6819909669
2009	27399.0767500887
2010	27817.0240456141
2011	26567.4639665484
2012	25556.3110855541
2013	26019.4710432238
2014	24649.8051909803
2015	23503.992501805
2016	23050.007629524
2017	22278.1631077779
2018	21802.032945148