Very few. Sometimes there are cases where a person who is mentally ill will do this, but it is rare.
Kids rare curious and bored, sometimes they just want to check out whats up there and see what they can find...it's biology and you never know what you're gonna get. if you eat boogers though, it can...
Most people eat bananas. It is unlikely you will find an exact statistic.
I would say everyone has tried eating paper before..
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