Year	gross (GPI)
1970	0.421369999647141
1971	0.438010007143021
1972	0.467299997806549
1975	0.501259982585907
1976	0.485460013151169
1978	0.558300018310547
1979	0.584010004997253
1980	0.549329996109009
1998	0.651849985122681
1999	0.75084000825882
2000	0.737049996852875
2006	0.922100007534027
2008	0.908850014209747
2009	0.893559992313385
2011	0.912090003490448
2014	0.915729999542236
2015	0.899469971656799
2016	0.993110001087189
2017	0.990890026092529
2020	0.995360016822815