Year	constant 2015 US$
2007	4651.776591732463
2008	4777.836783497469
2009	4232.215419166263
2010	4162.386600807203
2011	4302.250064707136
2012	4238.849838953325
2013	4189.534591498234
2014	4137.0556197565875
2015	4118.211865732334
2016	4099.604714613167
2017	4139.280164886199
2018	4175.06229261827
2019	4214.878145999812