Year	constant 2015 US$
1991	11616.630063985478
1992	13529.202472403595
1993	14473.011406632766
1994	15379.447329946883
1995	17117.62058002414
1996	17654.810602147205
1997	19233.29221164088
1998	19298.402625873623
1999	19779.304909208186
2000	20065.055248698794
2001	19561.541287248267
2002	20184.591420515397
2003	20364.748405243674
2004	21895.462750945157
2005	21248.915274838022
2006	21092.80824531246
2007	22089.957888202942
2008	20875.20538412086
2009	22195.64525085497
2010	23732.29470388447
2011	25534.80628797919
2012	25064.543218261522
2013	23267.44709380336
2014	24044.024256094166
2015	20256.356722871635
2016	22706.813563746196
2017	27597.686507441977
2018	28982.952986646662
2019	30081.71542174808
2020	34165.57852171276
2021	31240.07263393578
2022	32021.84475195977