What are the chances of getting a hermie from feminised plants grown in a good environment from good quality fem seeds: 10%, 50%, or would it just be the unlucky odd one?

Comments and examples appreciated ..

just done whiteberry,no males,opium no males, few years ago done dp blueberry,70 % trannies,dp powerplant 30% trannied, just do research some varity like blueberry are famos for trannies. plus fem seeds are a big part of growing now and breeders cant afford to get a bad name, i read some ware that sativas are more like to trannie on ya,

ive grown female grapefruit, trainwreck and lemon skunk, they were all fine
tw did throw the odd banana but they were sterile male parts anyway.
had regular seeds hermie (ie nirvana papaya) before but never had anything more than 1 or 2 seeds from a crop...no biggie
just bought some female bubblegummer...im yet to have a bad experience really..

usually its unlikely as long as genetics are good, if you do get pollen sacks its normally only a few early on in flower which can easily be removed so the plants carry on as normal.