Year	% gross
1971	4.48067998886108
1972	2.79702997207642
1973	3.13267993927002
1974	3.1117799282074
1975	2.60723996162415
1976	2.74494004249573
1977	2.15988993644714
1978	2.35341000556946
1979	2.60682010650635
1980	2.37315988540649
1981	2.748379945755
1982	3.08190989494324
1983	3.09371995925903
1984	2.93452000617981
1985	2.8537700176239
1986	2.90803003311157
1987	2.83925008773804
1988	2.93167996406555
1989	2.6628201007843
1990	2.72991991043091
1991	2.88784003257751
1994	2.64159989356995
1995	2.51101994514465
1996	2.53948998451233
1997	2.53714990615845
1998	2.50693011283875
1999	2.62629008293152
2000	2.15262007713318
2001	2.33550000190735
2002	2.60345005989075
2003	2.65650010108948
2004	3.03590989112854
2006	3.81318998336792
2007	4.16925001144409
2008	4.66294002532959
2009	7.13180017471313
2010	7.26822996139526
2011	9.12298965454102
2012	10.6680603027344
2013	13.7064304351807
2014	15.0394096374512
2015	17.5700397491455
2016	19.9624290466309
2017	21.3441600799561
2018	22.830680847168
2019	24.9799098968506
2020	29.7504291534424
2021	29.1930904388428