The number of leaks found on an aircraft is irrelevant. Whether they are acceptable leaks or not is.
Stain, seep, run? Location?
Any aircraft will leak. Manufacture of fuel cells able to flex,vibrate, be subject to extremes of temperature and yet be structurally sound and fuel tight is extremely difficult.
A more interesting figure to speculate about would be the number of leaks recorded per aircraft of any airline of your choice vs the Nimrod.