Authors:

Most human subjugates are young,” said Will. “Vampires like to acquire their subjugates when they’re youthful—prettier to look at, and less chance of diseased blood. And they’ll live a bit longer, though not much.” He looked pleased with himself. “Most of the rest of the Enclave wouldn’t be able to pass convincingly as a handsome young human subjugate—” “Because the rest of us all are hideous, are we?” Jem inquired, looking amused.

Cassandra Clare (2013). “The Infernal Devices: Clockwork Angel; Clockwork Prince; Clockwork Princess”, p.179, Simon and Schuster
Most human subjugates are young,” said Will. “Vampires like to acquire their subjugates when they’re youthful—prettier to look at, and less chance of diseased blood. And they’ll live a bit longer, though not much.” He