Times are usually measure from the bridge to gantry 'BTG times'. The best way of seeing how fast you are is to record it on video and then watch it when you get home. Timing whilst you are there and trying to better it, is asking fro trouble. Each lap will be different due to hold ups so from a stats perspective you'll never get a true idea of how fast you really can do it

Anyway, the ring is alot more than times. The first thing you should concentrate on is learning the corners and then the lines. 10years later, unless you are a local with year round access, you'll probably be experienced enough to start timing yourself

Looking at the vid from my one and only trip I was just under 10 minutes after 3 laps.

Paul.