Out of considerations for usability adjustments for website visitors with disabilities, I'm wondering what percentage of visitors is, that are unable to use mouse, and use only keyboard for navigation through elements on a website?
I have never seen or met anyone that can use keyboard, but cannot use mouse / or other pointing device like touchpad or touchscreen. So I'm also curious why they can't.
I am especially interested in the size of this group active in the IT-sector. But other stats will help too.