Year	gross (GPI)
1971	0.589179992675781
1972	0.602310001850128
1973	0.606320023536682
1974	0.611069977283478
1975	0.615360021591187
1976	0.605319976806641
1977	0.59961998462677
1978	0.598649978637695
1979	0.600629985332489
1980	0.605480015277863
1981	0.60140997171402
1982	0.599720001220703
1983	0.600069999694824
1984	0.597930014133453
1985	0.598699986934662
1986	0.602219998836517
1987	0.603380024433136
1988	0.609839975833893
1989	0.620959997177124
1990	0.631089985370636
1991	0.642620027065277
1992	0.651849985122681
1993	0.654190003871918
1994	0.658529996871948
1995	0.662710011005402
1996	0.665489971637726
1998	0.685199975967407
1999	0.699639976024628
2000	0.710929989814758
2001	0.724650025367737
2002	0.739920020103455
2003	0.750859975814819
2004	0.784850001335144
2005	0.801310002803802
2006	0.818229973316193
2007	0.838989973068237
2008	0.866330027580261
2009	0.886500000953674
2010	0.910120010375977
2011	0.927619993686676
2012	0.947329998016357
2013	0.967260003089905
2014	0.974290013313293
2015	0.974439978599548
2016	0.978280007839203
2017	0.984899997711182
2018	0.983500003814697
2019	0.994759976863861
2020	1.00919997692108
2021	1.01706540584564