Year	gross (GPI)
1973	0.500899970531464
1976	0.498580008745193
1977	0.526970028877258
1979	0.517599999904633
1980	0.530789971351624
1981	0.569419980049133
1984	0.616020023822784
1985	0.607200026512146
1986	0.627960026264191
1987	0.623650014400482
1988	0.716489970684052
1989	0.726050019264221
1990	0.753639996051788
2005	1.05332005023956
2006	1.05578005313873
2007	1.06429994106293
2008	1.08538997173309
2009	1.05958998203278
2010	1.07914698123932
2011	1.06452894210815
2017	1.10079967975616
2018	1.10387098789215
2020	1.14587998390198
2021	1.13545429706573