Year % gross 1971 9.04973030090332 1972 9.54197978973389 1973 10.3160200119019 1974 10.8484897613525 1975 11.1734399795532 1976 11.4678401947021 1977 11.9285001754761 1978 12.1656999588013 1979 12.6216897964478 1980 12.2088804244995 1981 13.5964002609253 1984 17.1977100372314 1985 18.2953491210938 1986 16.7345409393311 1988 18.793140411377 1989 16.1843891143799 1990 16.0375995635986 1991 15.2546901702881 2001 24.6340103149414 2011 39.1531982421875 2012 43.14794921875 2013 37.9642715454102 2015 38.5105590820312 2016 40.7056884765625 2017 40.0794486999512 2018 41.5716514587402 2019 58.9547309875488 2020 60.2446899414062 2021 70.7281265258789