Year	% gross
1971	0.0853699967265129
1974	0.193800002336502
1975	0.207800000905991
1976	0.329250007867813
1977	0.358559995889664
1978	0.478909999132156
1979	0.691919982433319
1980	0.959360003471375
1981	0.775600016117096
1982	1.13318002223969
1983	0.947520017623901
1984	1.04200005531311
1985	1.0731600522995
1986	1.11079001426697
1987	1.01119005680084
1988	1.11845004558563
1989	1.22747004032135
1990	1.36046004295349
1991	1.4694299697876
1992	1.38154995441437
1999	1.97054004669189
2000	1.90594005584717
2004	1.65167999267578
2006	1.08526003360748
2008	2.20260000228882
2009	2.36665010452271
2010	2.47221994400024
2011	2.89123010635376
2012	2.72516989707947