Year	gross (GPI)
1970	0.183850005269051
1981	0.386559993028641
1982	0.400000005960464
1983	0.408509999513626
1984	0.433580011129379
1985	0.447769999504089
1986	0.452019989490509
1987	0.460509985685349
1988	0.488020002841949
1989	0.552760004997253
1990	0.586480021476746
1991	0.620239973068237
1992	0.64776998758316
1993	0.659110009670258
1994	0.680920004844666
1995	0.693769991397858
1996	0.71288001537323
1999	0.750500023365021
2000	0.773230016231537
2001	0.824000000953674
2002	0.84495997428894
2003	0.871550023555756
2004	0.875720024108887
2005	0.912899971008301
2006	0.961290001869202
2007	0.999239981174469
2008	1.02560997009277
2009	1.05201995372772
2010	0.990473628044128
2011	1.07640480995178
2012	1.08080852031708
2013	1.07682585716248
2014	1.07024657726288
2015	1.0666207075119
2016	1.03501951694489
2017	1.02421712875366
2019	1.01865994930267
2020	0.989560008049011
2021	0.960808455944061
2022	0.923407137393951