Year	constant 2015 US$
1991	280.43236348998926
1992	204.24962136293865
1993	308.79120750867787
1994	224.97106565542032
1995	313.26961477435685
1996	384.5755507789604
1997	376.42928784843815
1998	407.5090863322866
1999	439.27265829202776
2000	452.20909900536896
2001	414.6771349938528
2002	430.36676341153384
2003	437.10333732710274
2004	444.610207865174
2005	395.7225324735658
2006	376.3104276190086
2007	419.22584868691104
2008	434.0679535701053
2009	452.29966877449806
2010	484.066320700728
2011	513.5465127496012
2012	502.7095089483041
2013	530.1998459633531
2014	556.2940157548214
2015	539.1601409010639
2016	520.6724707247638
2017	541.9637398638765
2018	526.4013482333798
2019	538.5271343752183
2020	541.8829868119082
2021	552.0177549179319
2022	523.4881269946571