Year	gross (GPI)
1970	0.513890027999878
1971	0.510890007019043
1972	0.509809970855713
1973	0.517599999904633
1974	0.520319998264313
1975	0.512359976768494
1976	0.510160028934479
1977	0.509739995002747
1978	0.514540016651154
1979	0.51061999797821
1980	0.508899986743927
1981	0.526570022106171
1982	0.550949990749359
1983	0.517960011959076
1984	0.49779000878334
1985	0.562680006027222
1986	0.626649975776672
1987	0.65038001537323
1988	0.657679975032806
1989	0.662039995193481
1990	0.663619995117188
1991	0.67043000459671
1992	0.674650013446808
1993	0.675719976425171
1994	0.667079985141754
1995	0.695860028266907
1996	0.700089991092682
1997	0.703270018100739
1998	0.704110026359558
1999	0.711310029029846
2000	0.7014200091362
2001	0.700959980487823
2002	0.697380006313324
2003	0.725660026073456
2004	0.713959991931915
2005	0.730170011520386
2006	0.724430024623871
2007	0.714349985122681
2008	0.735499978065491
2009	0.748369991779327
2010	0.757369995117188
2011	0.764069974422455
2012	0.7846599817276
2013	0.799350023269653
2014	0.79449999332428
2015	0.809979975223541
2016	0.810050010681152
2017	0.823509991168976
2018	0.835280001163483
2019	0.83762001991272