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I am trying to forecast a very typical sales data. I have tried Arima, ETS, Holtwinters and even neural networks but I can't get a model with more than 40% accuracy [Absolute sum of(forecast-Actual)/Sum of Actual]. Can anyone suggest me how to proceed?
Here is the data https://drive.google.com/open?id=1uugpk53hMyF8ncl30vkkwhuJeVYFEUql