Just some clarification for British-English speakers - I mean ill in general, not just vomiting. American-English speakers use the word 'sick' to mean 'ill' so I used both words in the title.
Used to about once a year. Usually went like this: Stressed out I tend to eat/drink too much, then sleep on my belly, wake up with a throat damaged/irritated by stomach acid, immune system can't handle it and gives me a fever. Tipping point kind of thing.
Stopped happening once I reduced work to 9 hours a week.
Once a year catching cold, generally. Last year went without me getting sick, which kinda sad, because it's only mild and safe inconvenience, that gives you free week off on a job.
RusticHopper wrote
Nearly never, prior to last summer I hadn't thrown up in five years.