Capture when votes are removed (or changed) from an idea

I need a way to create a report that tells me about changes to the number of votes an idea has received – say each week but timing isn’t that important.

The reason for this requirements is that we use the number of votes as a parameter within the idea and feature scorecard. It’s the same scorecard so gets automatically transferred from the idea to the feature but once promoted to a feature we then have to manually watch out for vote changes which would impact the feature score. We use the feature score to prioritise our backlog.