Year	% gross
1971	10.2434701919556
1972	11.2892999649048
1973	12.5936899185181
1974	13.9262599945068
1975	15.5881204605103
1976	17.6056709289551
1977	20.6418590545654
1978	21.4947605133057
1979	21.3249797821045
1980	21.6927108764648
1981	22.5837497711182
1982	23.7616291046143
1983	24.3710803985596
1984	25.1534996032715
1985	23.0072193145752
1986	24.0602798461914
1987	24.6259593963623
1988	22.6046199798584
1989	19.0175094604492
1990	17.3592300415039
1991	14.0800304412842
2001	31.2231101989746
2002	32.0277900695801
2003	28.0829792022705
2004	30.4142303466797
2005	31.1057300567627
2006	30.4521808624268
2007	32.9105796813965
2008	29.8937892913818
2009	31.0430297851562
2010	31.6649398803711
2011	26.9037494659424
2012	27.6573791503906
2013	29.8082695007324
2014	30.4505500793457
2015	33.117748260498
2016	31.3135299682617
2017	32.4095497131348
2018	35.7701683044434
2020	40.2633895874023
2022	37.6134986877441