Year	% gross
1973	13.7610597610474
1974	13.8279895782471
1975	13.9555501937866
1976	14.1362895965576
1977	14.2862195968628
1978	14.4383096694946
1979	14.525110244751
1980	14.5994300842285
1981	14.7241897583008
1982	14.4979400634766
1983	14.3695402145386
1984	14.1897401809692
1985	14.0212898254395
1986	14.3530101776123
1987	14.5202302932739
1988	14.7114095687866
1989	14.8698301315308
1990	14.8578701019287
1991	14.8423204421997
1992	14.9112300872803
1993	14.778639793396
1994	14.7563600540161
1995	14.8787202835083
1996	15.3928003311157
1997	14.3912000656128
1998	14.7420701980591
1999	13.8193502426147
2000	14.8921298980713
2001	15.638090133667
2002	16.8884296417236
2003	18.2988700866699
2004	19.1231708526611
2005	20.1599292755127
2006	21.2826805114746
2007	18.4953498840332
2008	18.6777095794678
2009	19.6088008880615
2010	19.4904499053955
2011	19.9797992706299
2012	22.4974098205566
2013	23.9034805297852
2014	25.199670791626
2015	26.6740798950195
2016	28.5145397186279
2017	29.0705890655518
2018	28.9615097045898
2019	29.2200908660889
2020	30.2020893096924