Year	current US$
2000	10.8297079476752
2001	10.391333765038794
2002	10.599181100296152
2003	15.55226779672719
2004	17.048588449859054
2005	19.082312539827914
2006	22.133394469860306
2007	24.43266653765602
2008	27.096445672049427
2009	24.641656480794747
2010	26.676050650938212
2011	28.602044082572252
2012	29.10175609984802
2013	31.816152054031804
2014	31.38053975787978
2015	28.98850072552673
2016	26.258049392775206
2017	25.120438455365885
2018	23.217675719967303
2019	22.98796658234435
2020	22.493687691850642
2021	25.31123269339777