Stuck on 18!

I have a question concerning the articles "Ace & Small Kicker", "Ace in Hand", and "Pocket Pairs & Over Cards". I have been able to determine most of the figures but I don't understand where they come up with the number 18. Could someone help me with this please. Thanks.

18 comes from the fact that there are 9 other people at the table each with two cards dealt to them.
So the articles show how to work out that none of those 18 cards are an ace.
HTH