Year	constant 2015 US$
1996	17758.418611006917
1997	18836.788264186882
1998	19531.89592546145
1999	20944.61607451618
2000	22859.271531958122
2001	23779.987741605797
2002	24562.033988608826
2003	24386.580889974648
2004	25235.519609955136
2005	25195.190197673495
2006	25185.297392829234
2007	25386.062667516486
2008	25506.539892845678
2009	25395.74378644933
2010	24855.39239499716
2011	25468.530719268132
2012	25796.678537909855
2013	26187.742780068806
2014	25937.99775251527
2015	26757.17451323729
2016	27170.98518020817
2017	28597.122581586846
2018	30056.855860278625
2019	31439.343392542545
2020	31061.63616987162
2021	32573.909123746813
2022	34358.33413774975