Year	gross (GPI)
2004	0.916459977626801
2005	0.910099983215332
2008	0.931559979915619
2009	0.934740006923676
2010	0.945129930973053
2011	0.94361013174057
2012	0.945813894271851
2013	0.954938352108002
2014	0.975361585617065
2015	0.975411593914032
2016	0.970537424087524
2017	0.964691042900085
2018	0.964869976043701
2019	0.978535830974579
2020	0.981068789958954