Here's a script that gives you an overview of your stats in a compact GUI that will disappear when you release the bound key, which is P by default.
Features frags, deaths, accuracy, flags scored (shows only in modes featuring flags), damage dealt, damage wasted, kills per death and damage dealt per death which is more accurate sort of measurement for efficiency modes, a personal favorite.
Enjoy, and give feedback. Report any bugs or problems that you may encounter!