Year gross (GPI) 1970 0.784650027751923 1971 0.658749997615814 1973 0.634630024433136 1974 0.613749980926514 1975 0.572350025177002 1977 0.574440002441406 1978 0.558839976787567 1979 0.619660019874573 1981 0.768490016460419 1983 0.680180013179779 1984 0.668799996376038 1985 0.697790026664734 1986 0.708570003509521 1994 0.495429992675781 2010 1.43405866622925 2011 1.40357434749603 2012 1.36602091789246 2013 1.35023927688599 2014 1.22690629959106 2015 1.35691344738007 2016 1.36694467067719 2017 1.35345578193665 2018 1.34266352653503 2019 1.39371860027313 2020 1.39930236339569 2021 1.38233625888824 2022 1.39708495140076