Year gross (GPI) 1971 0.254409998655319 1972 0.273889988660812 1973 0.262939989566803 1974 0.278219997882843 1975 0.304569989442825 1976 0.345829993486404 1977 0.328869998455048 1978 0.370180010795593 1979 0.376269996166229 1980 0.415369987487793 1981 0.423009991645813 1982 0.493389993906021 1983 0.476660013198853 1984 0.506110012531281 1985 0.514119982719421 1986 0.547829985618591 1987 0.561940014362335 1988 0.559960007667542 1989 0.558820009231567 1990 0.636900007724762 1991 0.647260010242462 1992 0.667400002479553 1993 0.702459990978241 1994 0.709429979324341 1995 0.716520011425018 2002 0.853569984436035 2003 0.879869997501373 2004 0.838630020618439 2005 0.883490025997162 2006 0.9028400182724 2007 0.858200013637543 2008 0.881139993667603 2009 0.912190020084381 2010 0.857879996299744 2011 0.987540006637573 2012 0.973680019378662 2013 0.994059979915619 2014 1.03698003292084 2015 1.11554002761841 2016 1.15164005756378