Year	% gross
1971	7.45301008224487
1972	9.03129005432129
1973	8.79467964172363
1974	9.32040023803711
1975	10.164400100708
1976	10.6340303421021
1977	12.5667896270752
1978	13.6967401504517
1979	14.9566402435303
1980	14.3676204681396
1981	16.8872604370117
1982	16.9195194244385
1983	16.7315196990967
1984	16.7107601165771
1985	17.4137496948242
1986	17.469539642334
1987	16.9667205810547
1988	18.194450378418
1989	17.151159286499
1990	17.3092994689941
1991	17.2168292999268
1992	16.4344692230225
1993	16.4979496002197
1994	15.1212596893311
1995	14.6056699752808
2002	12.5522699356079
2003	13.1426696777344
2004	15.1740503311157
2005	18.3284893035889
2006	21.0369606018066
2007	21.6712493896484
2008	22.2802906036377
2009	23.5956401824951
2010	25.6885604858398
2011	25.6436996459961
2012	30.2727794647217
2013	33.1396789550781
2014	47.3828811645508
2015	51.1659507751465
2016	46.5840187072754