Year	Number
2011	-1.72093844413757
2012	-1.44988763332367
2013	-1.51748442649841
2014	-1.64380407333374
2015	-1.67345762252808
2016	-1.80466055870056
2017	-1.94608294963837
2018	-2.03582668304443
2019	-1.984623670578
2020	-2.01043677330017
2021	-2.00442314147949
2022	-2.10399270057678