Year	% gross
1971	66.7465133666992
1972	68.0287628173828
1973	69.8488693237305
1974	71.2743072509766
1975	71.6042327880859
1976	74.1080703735352
1977	74.8802795410156
1978	74.8533935546875
1979	74.306022644043
1980	73.6737594604492
1981	72.7013397216797
1982	72.1064910888672
1983	72.5208969116211
1984	73.4953994750977
1985	74.5683670043945
1986	75.8105926513672
1987	76.8924789428711
1988	78.0436096191406
1989	79.3369598388672
1990	80.4427795410156
1991	81.8147277832031
1992	83.5382766723633
1993	85.1095962524414
1994	89.909538269043
1995	91.7001190185547
1996	92.709602355957
1997	93.3540802001953
1998	93.7566680908203
1999	94.9429397583008
2000	96.6562194824219
2001	98.4120407104492
2002	100.50154876709
2003	100.808708190918
2004	99.4125595092773
2005	99.561393737793
2006	99.9253616333008
2007	100.285369873047
2008	100.724807739258
2009	100.456443786621
2010	101.73217010498
2011	102.137672424316
2012	100.894371032715
2013	101.377876281738
2014	101.673309326172
2015	101.845062255859
2016	101.137489318848
2017	101.687789916992
2018	102.29711151123
2019	102.501480102539
2020	102.550926208496
2021	102.979560852051