I just did this (mail in now only) and it took about 3 weeks for them to get the license numbers back to me. Not too bad I guess, since you have to mail them to the other side of the country!
Just got mine back and it took a little under two weeks which I was impressed with. The best part is that its free which I find real weird since it is part of the government.I thought I would of had to pay something for sure