Year	α₁	β₁	α₂	β₂
2011	0.633	0.393	0.379	0.685
2012	0.631	0.398	0.289	0.724
2013	0.623	0.397	0.367	0.691
2014	0.632	0.388	0.485	0.604
2015	0.607	0.394	0.460	0.549
2016	0.601	0.394	0.504	0.535
2017	0.624	0.384	0.523	0.521
2018	0.645	0.367	0.584	0.458
2019	0.731	0.261	0.575	0.460
2020	0.696	0.314	0.556	0.491