Year	% gross
1970	1.41983997821808
1971	1.53812003135681
1972	1.65682995319366
1973	1.9379700422287
1975	2.61792993545532
1979	3.45214009284973
1987	3.87783002853394
1999	12.3024797439575
2000	23.6239490509033
2010	12.4186201095581
2012	14.0070495605469