Year	gross (GPI)
1996	1.56476998329163
1997	1.55596005916595
1998	1.53805005550385
1999	1.46703994274139
2000	1.44416999816895
2001	1.43072998523712
2002	1.43250000476837
2003	1.41085004806519
2004	1.39232003688812
2005	1.38153004646301
2006	1.36219000816345
2007	1.35813999176025
2008	1.37029004096985
2009	1.36789000034332
2010	1.35626339912415
2011	1.34088885784149
2012	1.31496822834015
2013	1.29739987850189
2014	1.30290186405182
2015	1.2750289440155
2016	1.27638924121857
2017	1.29509055614471
2018	1.29026246070862
2019	1.33272194862366
2020	1.38372647762299
2021	1.37963128089905
2022	1.39243590831757
2023	1.3925199508667