Year	Number
1996	-1.8921879529953
1998	-1.81796133518219
2000	-1.71313965320587
2002	-1.50747609138489
2003	-1.75101411342621
2004	-1.8110157251358
2005	-1.75917434692383
2006	-1.7624146938324
2007	-1.84848654270172
2008	-1.89333081245422
2009	-2.03949332237244
2010	-2.01058864593506
2011	-2.01552939414978
2012	-2.19676351547241
2013	-2.17476963996887
2014	-2.11436939239502
2015	-2.00146722793579
2016	-1.90966594219208
2017	-1.77831411361694
2018	-1.84629285335541
2019	-1.85240924358368
2020	-1.83675730228424
2021	-1.74533355236053
2022	-1.73443591594696