Year	Number
2011	-1.58625066280365
2012	-1.61496496200562
2013	-1.67964661121368
2014	-2.09334373474121
2015	-2.14849662780762
2016	-2.33603382110596
2017	-2.43996262550354
2018	-2.3204345703125
2019	-2.38367080688477
2020	-2.3163058757782
2021	-2.39656352996826
2022	-2.3898651599884