Year	% gross
1970	15.1453895568848
1971	15.1637201309204
1972	15.3917999267578
1973	15.5646200180054
1974	15.7058296203613
1975	16.0197296142578
1976	16.3276405334473
1977	16.6324691772461
1978	17.0241603851318
1979	17.4173107147217
1980	18.0230407714844
1981	18.5249500274658
1982	19.3003196716309
1983	19.9581699371338
1984	20.668270111084
1985	21.4382400512695
1986	21.8229293823242
1987	21.9201107025146
1988	21.899829864502
1989	21.5481491088867
1990	22.14089012146
1991	22.5958003997803
1992	22.3975296020508
1993	22.5864105224609
1994	23.0158004760742
1995	24.1988296508789
1996	24.5312995910645
1997	24.5527400970459
1998	25.2849502563477
1999	25.369930267334
2000	25.3563594818115
2001	26.1233406066895
2002	26.6879901885986
2003	27.1208896636963
2004	28.1534194946289
2005	28.9987907409668
2006	30.385139465332
2007	31.550910949707
2008	33.1645584106445
2009	34.3729782104492
2010	35.4808006286621
2011	36.4360313415527
2012	37.5930786132812
2013	38.8744812011719
2014	39.7961692810059
2015	39.7237815856934
2016	40.1702308654785
2017	40.506950378418
2018	40.6061515808105
2019	40.7041015625
2020	41.1389503479004