I'm kind of afraid to ask this one..?

Alright, this one is somewhat racist, but it really eats at my brain. It's about.. well, okay. So I know that lots of people from all different ethnicities walk slowly. Alternatively, plenty of people from all different ethnicities are power walkers. Alright, I'll just say it: it's about black people, okay? Of course not all black people are like this; that's obvious. And I didn't come here to hurt anyone's feelings, just to ***** about a pet peeve. Okay- so whenever I'm walking through a crowded place, such as a mall or my school's hallways, there are always people, sometimes groups of them, who walk as fast as snails and cause other people to have to find a way around them. It seems that about 90% of the time, they're black. Why the heck is that? Is it some stupid cultural thing? Is it only like that in Georgia (US)? I remember one time in cl, we were doing this environmental science project, so we all went down this long path behind the school so that we could place some clay worms in an area where they wouldn't be affected by human activity. My cl is mostly black. Well, the non-black minority of my cl got there first and completed the ignment. Then, EVENTUALLY, everyone else arrived and did it. Then we left. Once again, the non-black minority made it back to cl before the middle of the cl period. EVERYONE ELSE, I'm not kidding; no exaggerations or exceptions, made it shortly before the bell rang for classes to switch. That event really made me think about it. Why?