How many vampires are there in Twilight?

This answer is according to the books only!

In Eclipse, the is 10 werewolf's that are named Jacob, Sam, Paul, Jared, Quil, Embry, Seth, Leah, Collin and Brady. In Breaking Dawn though it is told from Bella's perspective and at the end when the Voultri are there Bella said there was 'about' sixteen wolfs surrounding them. Their names were not mentioned at all.