Year	constant 2015 US$
1998	12183446989.05679
1999	9786474664.303072
2000	6955437089.160618
2001	7688624480.702508
2002	8618667513.782627
2003	9322067154.13289
2004	12780116724.255709
2005	6014054100.811076
2006	15636757641.400396
2007	21682564260.1851
2008	27388051081.262833
2009	21928989324.744133
2010	19858530096.627728
2011	22001046228.54666
2012	26475440093.715637
2013	28918333180.329308
2014	24048895496.21699
2015	28628348504.551365
2016	30122493206.457146
2017	32468367390.453796
2018	29868421605.128593
2019	27390927075.306988
2020	28127101416.212597
2021	23401978545.719044