Year % gross 1971 7.15785980224609 1972 7.44429016113281 1973 7.6490797996521 1974 8.13764953613281 1975 8.75345039367676 1976 10.5709600448608 1977 12.5503301620483 1978 10.9452600479126 1979 11.5674295425415 1980 11.2486600875854 1981 11.3914203643799 1982 11.5983200073242 1983 12.0066299438477 1984 12.2898397445679 1985 13.7802696228027 1986 12.7903099060059 1987 16.1415100097656 1990 19.779109954834 1991 23.173469543457 1992 23.5444793701172 1993 30.2382793426514 1994 33.4518814086914 1995 36.1944313049316 1996 38.6572494506836 1998 44.0282592773438 1999 45.7186889648438 2015 61.8582000732422 2016 63.2655715942383 2017 64.1698226928711 2018 65.0279083251953 2019 65.9340515136719 2020 67.7980194091797 2021 71.8742980957031