Depends. Usually around 30 searches on working days since I have to research about stuff. But on a regular day, only about 5? LOL
I don't count, but it's surely over 50 a day; I constantly search things on Google and I sometimes I don't even realize it.
Around 50-60 sounds right for me seeing as I'm at an SEO firm. Many times we do searches just to see what comes up for rankings on a regular basis.