Year	% gross
1970	16.2837200164795
1971	16.0268001556396
1972	15.8143396377563
1973	15.8793296813965
1974	16.06422996521
1975	16.6729297637939
1976	18.4127407073975
1977	21.4881191253662
1978	20.2358894348145
1979	20.4378509521484
1980	21.4459209442139
1981	22.9270706176758
1982	23.2894401550293
1983	24.2501602172852
1984	25.2279300689697
1985	26.4426097869873
1986	27.7443294525146
1987	28.9836597442627
1988	29.7250308990479
1989	29.4167900085449
1990	29.3794403076172
1991	29.2596797943115
1992	29.5258407592773
1993	29.6630401611328
1994	29.5470695495605
1995	30.027530670166
1996	30.5359897613525
1997	28.7565402984619
1998	31.8560905456543
1999	32.5820617675781
2000	33.4483909606934
2001	34.0309906005859
2002	33.857120513916
2003	34.7647018432617
2004	36.060489654541
2005	37.8261795043945
2006	39.827091217041
2007	41.2785682678223
2008	42.8905792236328
2009	44.5050010681152
2010	46.4303398132324
2011	49.1513290405273
2012	52.1518516540527
2013	53.9950103759766
2014	54.1205406188965
2015	56.184268951416
2016	57.8153915405273
2017	59.4470710754395
2018	60.2916984558105
2019	61.0913505554199
2020	61.2998313903809