Year	% gross
1970	9.75080966949463
1971	9.67101001739502
1972	9.56499004364014
1973	9.50088024139404
1974	9.3528003692627
1975	9.66679954528809
1976	10.1853704452515
1977	10.5544700622559
1978	10.5005903244019
1979	10.8255395889282
1980	11.1000003814697
1981	11.6263103485107
1982	11.7414197921753
1983	11.9294996261597
1984	12.1975803375244
1985	12.5704298019409
1986	12.4955396652222
1987	12.6209096908569
1988	12.474419593811
1989	12.8197803497314
1990	12.7577896118164
1991	12.8769397735596
1992	12.9196395874023
1993	13.0961999893188
1994	13.2901802062988
1995	13.4446496963501
1996	13.74351978302
1997	13.9227895736694
1998	14.1951198577881
1999	13.991720199585
2000	14.4194803237915
2001	14.3770599365234
2002	14.6273097991943
2003	15.0507001876831
2004	15.5322704315186
2005	16.2476997375488
2006	18.1421794891357
2007	18.1281604766846
2008	19.7129192352295
2009	22.6638793945313
2010	23.1570701599121
2011	23.2303009033203
2012	23.8817195892334
2013	24.1138401031494
2014	26.3894004821777
2015	26.8733005523682
2016	26.8842296600342
2017	27.1281108856201
2018	27.1865406036377
2019	27.7719097137451
2020	28.2497997283936