Year	current US$
2011	27461355189.471985
2012	31534003912.039684
2013	34143591415.304787
2014	39264024276.08933
2015	41277918132.50803
2016	44254737521.32574
2017	50207227370.422935
2018	51565534601.56365
2019	52579729788.32528