Year	% gross
1971	12.3704500198364
1972	12.5088500976563
1974	12.2441701889038
1975	12.6160297393799
1976	13.5232400894165
1977	15.4359102249146
1978	15.8562898635864
1980	19.4731502532959
1981	24.7117195129395
1982	32.3621597290039
1983	38.6856803894043
1984	43.3077392578125
1985	49.1025695800781
1986	54.3186492919922
1987	58.0363616943359
1988	59.7755317687988
1989	60.6704711914063
1990	60.3436698913574
1991	61.5849113464355
1992	62.1846008300781
1993	62.8827590942383
1994	64.799919128418
1995	66.7916793823242
1996	68.5485992431641
1997	70.1620483398438
1998	71.9301910400391
1999	73.1392822265625
2000	73.9441375732422
2001	74.5163803100586
2002	75.0322265625
2003	79.9629211425781
2004	82.8413925170898
2005	91.1791076660156
2006	99.4784088134766
2007	105.684837341309
2008	105.38362121582
2009	102.451942443848
2010	101.677711486816
2011	102.80647277832
2012	104.525550842285
2013	70.9970169067383
2014	71.7276306152344
2015	72.0023193359375
2016	72.1698913574219
2017	73.7250671386719
2018	72.79931640625
2019	70.9686431884766
2020	70.5982513427734
