Year	constant 2010 US$
1991	3223.73066339835
1992	3338.88585092569
1993	3170.434437448
1994	2817.57474313813
1995	2911.72599766506
1996	2738.56045854189
1997	2797.8577462661
1998	2657.43815193587
1999	3067.34373925798
2000	2919.66179078923
2001	2698.29796211965
2002	2825.39644321461
2003	2882.40634581151
2004	2747.0566029087
2005	2645.92407065927
2006	2800.73163296365
2007	3067.20478270837
2008	2904.01406028284
2009	2468.52565002183
2010	2574.20037825596
2011	2332.79051954176
2012	2431.44975738145
2013	2362.65098815121
2014	2516.90718985597
2015	2460.82021778958
2016	2499.51933978314
2017	2434.05077133695
2018	2412.66439051978