That stat is legit. It's backed by speech pathology research and global estimates. The thing is, stuttering isn't always obvious. A lot of people have mild or situational stutters that you might not notice unless you're really close to them or hear them speak under pressure (like public speaking or interviews). Also, some have learned to mask it really well (word switching, slowing down, avoiding certain sounds). Even if someone does stutter, you might never hear it unless they tell you. Plus, stuttering is more common in kids and tends to decrease with age. I've never met someone with a stutter in real life. Not that I'm the type of person who likes knowing lots of people, to be honest.