Year	Number
2011	-1.43032848834991
2012	-1.15658330917358
2013	-1.73032867908478
2014	-2.64657664299011
2015	-2.37200832366943
2016	-2.41249680519104
2017	-2.44623565673828
2018	-2.43455958366394
2019	-2.51834392547607
2020	-2.19166994094849
2021	-2.28720140457153
2022	-2.21005392074585