Year	gross (GPI)
1994	1.02268004417419
2003	0.999660015106201
2004	0.994069993495941
2005	0.989530026912689
2006	0.984759986400604
2007	0.981660008430481
2008	0.976689994335175
2009	0.984179973602295
2011	0.983690023422241
2012	0.98198002576828
2013	0.983479976654053
2014	0.977429986000061
2015	0.97680002450943
2016	0.982789993286133
2017	0.975179970264435
2018	0.970380008220673
2019	0.972750008106232