Year	% gross
1971	1.45869994163513
1972	1.16153001785278
1973	1.59329998493195
1974	1.88752996921539
1975	2.13752007484436
1976	2.2610399723053
1977	2.56916999816895
1978	3.01132011413574
1979	3.48610997200012
1980	4.23540019989014
1981	4.33838987350464
1982	5.13556003570557
1983	5.2652702331543
1984	5.35489988327026
1985	5.37463998794556
1986	5.28874015808105
1987	5.26245021820068
1988	5.56685018539429
1989	4.6139497756958
1990	4.57280015945435
1991	4.54486989974976
1992	4.98847007751465
1993	5.58304977416992
1999	3.67968988418579
2000	5.25535011291504
2001	4.21126985549927
2002	3.76958990097046
2003	3.80226993560791
2009	5.8192400932312
2011	7.91929006576538
2012	9.07367992401123
2013	8.57032012939453
2015	11.5909996032715
2017	12.2616300582886