Forum:Character ages are all wrong

The pages for all of the kids, Karkat, Kanaya, and Terezi all say that they're either 20 or 21, for some reason. I had originally assumed that it was an automatic thing, since John, but that doesn't explain why it affected the Troll and Alpha Kid's ages, as well, nor why Rose and Jade are listed as 21 and 20, respectively, while their listed birth dates are only three days apart. I'm assuming that someone read too much fanfiction, and decided to "fix" the ages, or something.