Wow, I thought I knew my one-hit-wonders, but this game is *tough*! I never made it past round 3. We probably have different charts in mind, since I'm in the UK.
It looks like your rounds/high scores are screwed somehow. I would sometimes start a new game in the same round as the last one I'd played. And in the 2010's category I got the first answer wrong and ended up with -563 points.
Anyway, good work getting this finished, now get started on your next game!