I think someone has had physical access to my iphone 5 and installed a spy software into it?

My iphone is not jailbroken. Is it possible he jailbroke my iphone to install a virus onto it and then unjailbroke my iphone to how it was before it was jailbroken so I don't notice any differences with my iphone?

anyway the bottom line is: what are the chances someone could have installed a spy software onto my iphone if my iphone is not jailbroken? Give me a probability from 0 to 100 that my iphone has a spy software installed into it secretly

Iphones are really secure and they also don't allow garbage like that in the appstore (which is great because like the malware crazy windows that all other phones are now struggling against).

Anything is possible, for sure, but that would be a lot of higher-level work. If you are a high ranking political figure or a military leader, maybe. If you are Joe on the block, what would they get from it to to make it worth that much effort? Are you planning a huge jewel heist? Knocking-over a bank? Over-throwing a Latin American country? Close to curing cancer? Fixing next year's Super Bowl? Gotta be something in it for them…

Probability 100
yes, There are chances to hide jailbreak after install the Spy application. Spy app like: iKeyMonitor works in hidden mode also you can hide jailbreak (cydia)