Year	% gross
1973	26.3432903289795
1974	26.2499809265137
1975	27.5453395843506
1976	29.4640197753906
1977	29.9840908050537
1978	29.7862491607666
1979	30.6582298278809
1980	30.5365200042725
1981	29.6139907836914
1982	29.9670295715332
1983	30.6296405792236
1984	30.3597393035889
1985	30.1082191467285
1986	30.416690826416
1987	29.9984703063965
1988	30.9949398040771
1989	31.1231803894043
1990	31.244270324707
1991	32.434440612793
1992	32.638111114502
1993	33.8679008483887
1994	33.7555809020996
1995	34.161319732666
1996	34.8414916992188
1997	35.1174087524414
1998	34.5877304077148
1999	34.885311126709
2000	35.0025787353516
2001	35.7787590026855
2002	37.265998840332
2003	37.7045211791992
2004	39.4837493896484
2005	40.322208404541
2006	40.3488616943359
2007	40.7763214111328
2008	42.2535591125488
2009	43.3162117004395
2010	43.2066688537598
2011	44.2525482177734
2012	43.821949005127
2013	44.5004196166992
2014	44.6563186645508
2015	45.6748390197754
2016	45.273509979248
2017	45.7033615112305
2018	45.802059173584
2019	46.500919342041
2020	45.4303894042969