Year	% gross
1974	25.9601402282715
1975	27.1863899230957
1976	28.6791591644287
1977	29.5042991638184
1978	29.3299293518066
1979	30.3373107910156
1980	30.0102291107178
1981	29.1755409240723
1982	29.53782081604
1983	30.1995391845703
1984	29.9021892547607
1985	29.6631603240967
1986	30.0009593963623
1987	29.6138496398926
1988	30.5620498657227
1989	30.734619140625
1990	30.8419990539551
1991	32.0630187988281
1992	32.2028617858887
1993	33.4675216674805
1994	33.3121299743652
1995	33.783748626709
1996	34.4831314086914
1997	34.6266899108887
1998	34.0498580932617
1999	34.4301986694336
2000	34.5453987121582
2001	35.266529083252
2002	36.6719818115234
2003	37.3033599853516
2004	39.2768516540527
2005	40.2120780944824
2006	40.1818695068359
2007	40.4191513061523
2008	41.6967887878418
2009	42.8363800048828
2010	42.8883094787598
2011	43.9904403686523
2012	43.5728797912598
2013	44.2387199401855
2014	44.2341690063477
2015	45.2201614379883
2016	45.0127296447754
2017	45.2757911682129
2018	45.3936614990234
2019	46.0075416564941
2020	45.0801010131836