Driving test pass rates vary between the the UK's 414 driving test centres. Do not let your local test centres' pass rate affect you. The pass rate only provides information on previous candidates, not you. For your practical test, make sure you are confident that you can do everything safely, under control and without any assistance from your instructor. Observations are the biggest downfall for most pupils. You should know what is happening around you at all times.
Below you will find pass rate statistics for the UK, each county and each driving test centre.