Year	current US$
2000	10.836317554626397
2001	10.40176843177266
2002	10.60497284664233
2003	15.559356445741724
2004	17.057640233362505
2005	19.092404840665576
2006	22.142974516825348
2007	24.440064728528963
2008	27.107546742642057
2009	24.650199964131186
2010	26.685064836907962
2011	28.611204674237914
2012	29.11088067612682
2013	31.824435597847415
2014	31.39611797388491
2015	29.001997026591138
2016	26.273025870918875
2017	25.134699715855813
2018	23.232948250858144
2019	23.002713557949033
2020	22.50546006467315
2021	25.322538287650477