I know there is a 20%, 50% and 80% notification when exploring the map...but if i think there should be a circle or a bar that indicates the progress, no need for the actual number just a visual representation.

After 80% it gets hard to know if i need to explore 3 more systems or just 1 to get to 100%.  Sometimes there are systems that are not connected via the "starlanes" or wormholes, solo systems that are hard to find.