Year	gross (GPI)
1970	0.541649997234344
1971	0.539870023727417
1972	0.53150999546051
1973	0.526279985904694
1974	0.519949972629547
1975	0.516539990901947
1976	0.514750003814697
1977	0.50534999370575
1978	0.500779986381531
1979	0.49235999584198
1980	0.496450006961823
1981	0.494359999895096
1982	0.502990007400513
1983	0.499689996242523
1984	0.499020010232925
1985	0.497680008411407
1986	0.500609993934631
1987	0.502820014953613
1988	0.501820027828217
1989	0.50025999546051
1990	0.510730028152466
1991	0.509010016918182
1992	0.511240005493164
1993	0.51705002784729
1994	0.51596999168396
1995	0.511349976062775
1996	0.513790011405945
1997	0.515309989452362
1998	0.509530007839203
1999	0.512880027294159
2000	0.527750015258789
2001	0.531989991664886
2002	0.551980018615723
2003	0.541429996490479
2004	0.553409993648529
2005	0.566209971904755
2006	0.590929985046387
2007	0.581920027732849
2008	0.580320000648499
2009	0.582189977169037
2010	0.584879994392395
2011	0.600109994411469
2012	0.620809972286224
2013	0.617550015449524
2014	0.623820006847382
2015	0.631420016288757
2016	0.63782000541687
2017	0.643480002880096
2018	0.646340012550354
2019	0.65777999162674
2020	0.665409982204437