I can't...I have them memorized. I know that's what they are since they are right next to the gates, and you'll notice there's a single red mark next to single gate numbers, and double red marks next to double gate numbers, e.g. in the rotunda, on the right side is gates 1, 2 and 3, and opposite are gates 16, 17 and 18.

Since one of the purposes of the map is to show those who don't know the airport very well the location of the gates, it's fairly useless.