Thus, one can say the variation direction on your chart (after correction for the annual increase or decrease as given on the chart legend) is 20° W or -20° of north i.e. 340° on the three figure system.
Ngoko ke omnye angathi iindidi zeendlela kwitshati yakho (emva kolungiso lonyuko ngonyaka okanye ukwehla ngokunikiweyo kwitshati yelnkcazelo u 20W okanye-20° womntla umzekelo 340° kwisixokelelwano seziqu ezintathu).