Keep history from "data value" after "refresh data" from the data via "get data from website?

Engo92 

It slightly depends on your source data, but let assume it is as the table on the left

named Source. On first step we query it, add custom column with current date as

assign proper data types, rename query as History and load it back to Excel sheet (green table on the right).

As next step query the History, we will have it as History (2), keep it as connection only. 

Now edit History (2). Steps are:

- we assign proper types

- append History query

- add Index column to fix table in memory, otherwise for large table we may receive wrong result

- sort table (by dates from oldest to newest)

- select Date and Value columns and Remove duplicates

- remove Index column, we don't need it any more

Now open History (2) in advanced editor and copy script between let and in

Close it, open in Advanced editor History query and paste code before in

Manually correct the code:

- add comma at the end of #"Reordered Columns" step

- Rename second Source as SourceHistory

- since we have two steps #"Changed Type" rename second one to #"Changed Type 01"

- Return result of #"Removed Columns" step (after in)

Save the query and we may delete History (2) query.