Year	% gross
1971	0.278420001268387
1973	0.32311999797821
1974	0.290899991989136
1975	0.402940005064011
1977	0.429529994726181
1978	0.423669993877411
1980	0.463160008192062
1981	0.453330010175705
1984	0.549430012702942
1985	0.592689990997314
1986	0.624379992485046
1987	0.60971999168396
1988	0.654370009899139
1989	0.737039983272552
1990	0.957729995250702
2001	2.11559009552002
2002	2.50592994689941
2003	2.92148995399475
2004	3.271320104599
2009	5.92379999160767
2010	6.71844005584717
2011	7.99563980102539
2012	7.52440023422241
2013	8.01700019836426
2014	7.7692699432373
2015	8.13613986968994
2016	8.22667980194092
2017	7.45798015594482
2018	7.2117600440979
2019	6.63355016708374
2020	8.0903902053833
2021	7.80600023269653
2022	7.94463014602661
