Year	gross (GPI)
1970	0.23581999540329
1971	0.261229991912842
1972	0.28014001250267
1973	0.29381000995636
1974	0.282260000705719
1975	0.307539999485016
1976	0.330639988183975
1977	0.346399992704391
1978	0.379299998283386
2002	0.764339983463287
2007	1.05597996711731
2009	1.06544005870819
2010	1.02903997898102
2011	1.01497995853424
2012	1.02506005764008
2013	1.0511599779129
2014	1.10714995861053
2015	1.14982998371124
2016	1.01514029502869
2017	1.01237511634827
2018	1.03812992572784
2019	1.13011002540588
2020	1.09870398044586