Year	gross (GPI)
1972	0.92865002155304
1987	0.852550029754639
1988	0.942820012569427
1989	0.987070024013519
1990	1.06588995456696
1994	0.978380024433136
2001	1.07377004623413
2002	1.05509996414185
2003	1.09994995594025
2004	1.110720038414
2005	1.12636995315552
2006	1.17934000492096
2007	1.20568001270294
2008	1.11760997772217
2009	1.18921995162964
2010	1.18525004386902
2011	1.16322994232178
2012	1.1800400018692
2013	1.15306997299194
2014	1.13718998432159
2015	1.11571002006531
2016	1.10441994667053
2017	1.09838998317719
2018	1.10310995578766
2019	1.08632004261017