What is the usual cause for one cylinder being different (in my case, higher) than the rest? (All results were after 7 compression strokes)

Planning on boosting.. 235,000kms (150,000miles) on the motor, doesn't smoke or burn any more oil than usual.

All good to go?

 

those number look okay to me for a car with 150,000 miles... as long as one of them isn't FAR out..

 

look okay, number seem consistent