Year	gross (GPI)
1991	0.997699975967407
1992	1.01986002922058
1993	1.0168399810791
1994	1.04465997219086
1995	1.03629004955292
1996	1.03712999820709
1997	1.03380000591278
1998	1.01723003387451
1999	1.01603996753693
2000	1.01221001148224
2001	1.00260996818542
2002	0.992590010166168
2003	0.984839975833893
2004	0.986159980297089
2005	0.990249991416931
2006	0.99456000328064
2007	0.999939978122711
2008	0.996469974517822
2009	0.991609990596771
2010	0.984120011329651
2011	0.977479994297028
2012	0.981029987335205
2013	0.980449974536896
2014	0.985889971256256
2015	0.990239977836609
2016	0.993120014667511
2017	0.996100008487701
2018	0.997439980506897
2019	0.999930024147034
2020	1.00295996665955