Don't worry, I've done that already. The problem is that the parties at the top for me are all tiny parties without a realistic chance to win. If I only filter by parties that were elected last time, the first party is ... FDP at 55.7%. Then SPD at 54.3%. All other parties are below 50%.
It's tough electing a party that way.
Ah, well that makes sense. Thanks for clarifying.