
1 - Transpose the table
2 - Unpivot all the columns other than Measure
3 - Rename the Measure column as year
4 - Change the data type of the year column to Date
Reference:
https://support.microsoft.com/en-us/office/unpivot-columns-power-query-0f7bad4b-9ea1-49c1-9d95-f588221c7098