Year	% gross
1976	15.0766696929932
1977	15.1097497940063
1978	15.6430902481079
1979	15.8461303710938
1980	16.1266193389893
1981	15.6025800704956
1982	15.4012403488159
1983	15.2842197418213
1984	15.2805099487305
1985	15.3628902435303
1986	15.4749402999878
1987	15.8487596511841
1988	16.0720806121826
1989	16.005199432373
1990	16.1157302856445
1991	16.1464099884033
1992	16.1472797393799
1993	16.165470123291
1994	15.7217102050781
1995	15.761890411377
1996	15.8400497436523
1997	15.8915395736694
1998	16.0590496063232
1999	12.0467700958252
2000	13.6336297988892
2001	13.6270999908447
2002	15.1698598861694
2003	16.8087501525879
2004	19.3293495178223
2005	19.1648807525635
2006	21.3405609130859
2007	22.665620803833
2008	21.708610534668
2009	23.9417095184326
2010	24.4568691253662
2011	29.0754203796387
2012	33.9089508056641
2013	38.7616310119629
2014	20.5793800354004
2015	23.2828407287598
2016	22.9709491729736
2017	23.3105392456055
2018	23.3395500183105
2019	23.7923107147217
2020	24.0765209197998