Year	gross (GPI)
1971	0.530520021915436
1972	0.555109977722168
1973	0.567759990692139
1974	0.574199974536896
1975	0.585089981555939
1976	0.590489983558655
1977	0.601040005683899
1985	0.714709997177124
1988	0.689059972763062
1990	0.712800025939941
1991	0.746460020542145
1992	0.759909987449646
1993	0.78737998008728
1994	0.810490012168884
1995	0.841729998588562
1997	0.898020029067993
1999	0.916519999504089
2000	0.926750004291534
2001	0.931400001049042
2002	0.939180016517639
2003	0.93843001127243
2004	0.961290001869202
2005	0.964399993419647
2006	0.969129979610443
2007	0.999249994754791
2008	0.958729982376099
2009	0.94336998462677
2010	0.937399983406067
2011	0.935899972915649
2012	0.930779993534088
2013	0.931289970874786
2014	0.931349992752075
2015	0.935649991035461
2016	0.953999996185303
2017	0.963060021400452
2020	0.989520013332367