Year	gross (GPI)
1971	0.620109975337982
1972	0.631919980049133
1982	0.870000004768372
1983	0.826860010623932
1986	0.817480027675629
1987	0.814400017261505
1988	0.795099973678589
1989	0.832369983196259
1990	0.913469970226288
1991	0.913450002670288
1992	0.858630001544952
1998	0.827970027923584
2008	0.845690011978149
2009	0.836049973964691
2010	0.799430012702942
2011	0.629220008850098
2015	0.874130010604858
2016	0.903363227844238
2017	0.928512394428253
2018	0.936736643314362