What are the spawn chances of items from lunchboxes?

I have found roughly 50 lunchboxes out in the wasteland now and I have noticed the wide variety of things that spawn from them. The occurrence of anything useful seems very low though. Does anyone know the probability of the items that are eligible to spawn from the lunchboxes?

From the wikia, the possible items you can get are:

Models

Mr. Gutsy model

Mr. Handy model

Protectron model

Sentry bot model

Eyebot model

Aid Items

Nuka Cola

Ice cold Nuka Cola

Nuka Cola Quantum

Ice cold Nuka Cola

Quantum Nuka

Cherry Bubblegum

Noodle cup

Gum drops

Dandy Boy Apples

Junk

Plastic fork

Plastic knife

Plastic spoon

Table knife

Dinner fork

Table spoon

Chalk Baseball

Economy wonderglue

Pen Pencil

Wonderglue

Ammo

Other

Fusion core

There does not seem to be a proven formula for drop rate of any of these items, but it is worth noting that you are able to reload a save if you get an undesirable item, in order to try to get a better one.