Year	% gross
1971	0.933030009269714
1972	1.69370996952057
1973	2.47389006614685
1974	3.00692009925842
1975	3.29069995880127
1976	4.0120701789856
1977	4.10656023025513
1978	2.5216600894928
1980	3.46862006187439
1981	3.97886991500854
1983	5.29679012298584
1984	5.46563005447388
1985	5.87685012817383
1986	6.13655996322632
1999	4.37391996383667
2001	7.45367002487183
2002	7.33924007415771
2006	9.819899559021