How To Keep Historical Data In Excel. Don’t overwrite previous data, add new data to your list instead. So it will show 10/16/17 67.40 then tomorrow/next day 10/17/17 will record a value that report is refreshed as xx.00 and keep the previous data of 67.40.
Add a sheet called data. Exponential smoothing, like moving averages, is based on smoothing past data trends. Next, click the “historical” tab at the top right of the quote: