Depends. say 85 to 90, depending on which one and the type of aircraft.
Also keep in mind that US carriers are often, but not always nuclear, for added space for fuel.
I forget who posted the question, but in regards to Japan and nuclear armed ships, the issue was not originally nuclear weapons per se. the issue revolved around the grounding of the Enterprise on a sand bar on the approaches to Tokyo Bay c. 1985. The debate and concern then was what would happen if the bottom were torn out of nuclear-powered warship. It naturally then degenrated into a "worst-case" scenario about a loose nuc.
As of 1987, no American surface ships (officially) carry nuclear weapons.
And our Navy pilots are exceedingly better trained and more skilled. Not sure how long we'll be able to say that if a real oil crisis occurs. But I hope it's always true.