Year	% gross
1971	4.39885997772217
1972	4.57649993896484
1973	4.59747982025146
1974	4.185959815979
1975	4.72098016738892
1976	4.55753993988037
1977	4.82107019424438
1978	4.02471017837524
1979	4.01131010055542
1980	3.73351001739502
1981	3.73902010917664
1982	4.0988302230835
1983	4.72733020782471
1984	5.22002983093262
1985	5.76227998733521
1986	5.81972980499268
1987	6.49717998504639
1988	6.72788000106812
1989	6.59207010269165
1990	7.30727005004883
1991	7.02002000808716
1992	7.13289022445679
1993	7.44781017303467
1994	7.3901801109314
1995	7.37658977508545
1996	7.53646993637085
1997	7.86444997787476
1998	8.14099979400635
1999	8.6469202041626
2000	8.97883033752441
2001	9.22008037567139
2002	9.42082023620605
2003	9.85202980041504
2004	10.2378702163696
2005	10.3061304092407
2006	10.3935203552246
2007	9.53999996185303
2008	9.76646041870117
2009	9.23880958557129
2010	9.25580978393555
2011	10.6890497207642
2012	10.6991100311279
2013	5.65537023544312