It won't vary too much. Each driving test is 100-odd points, and you can lose up to about 8 IIRC. If you do something really stupid like go through a red light, then they can fail you just for that one action as well.
Apparently I was only one point away from failing, but that's still a pass.
ha ha i got 94 for my driving test, but i failed on two instances 'failing to give way when necessary'.... judging gaps was the downside.... oh wells..