iOS as a whole is outpacing Android among U.S. mobile subscribers, according to the latest data from comScore. The research firm reports that iOS enjoys an installed base of 37.9 million users among U.S. mobile subscribers age 13 and up, good for a 16.2 percent share, compared to a base of 23.8 million users for Android, good for a 10.2 percent share. Among the iOS users, the installed base of iPhones slightly exceeded that of iPod touches, both of…