Year	gross (GPI)
1970	0.741699993610382
1971	0.759419977664948
1972	0.737079977989197
1973	0.745549976825714
1974	0.779079973697662
1975	0.815599977970123
1976	0.843529999256134
1977	0.880680024623871
1998	1.01721000671387
1999	1.01065003871918
2000	1.01367998123169
2001	0.996039986610413
2002	0.991639971733093
2003	0.971920013427734
2004	0.92602002620697
2005	0.961889982223511
2006	0.954479992389679
2007	0.841840028762817
2009	0.946420013904572
2010	0.946479976177216
2011	0.936869978904724
2012	0.944719970226288
2013	0.973249971866608
2014	0.991859972476959
2015	0.999899983406067
2016	0.994629979133606