Large amount of team members.

[Or 2230]

Hello there FIRST community
Recently, our team, that traditionally had 30-40 members, has faced a new problem: 40 new students signed up to our team, which makes us a team of 70 students.
Our team never had any process of deciding which students can join our team and which can't, because of the fact that we believe that everyone who wants to join FIRST should have the opportunity to do so.
What do you guys do in your teams? Do you sort the students or do you have a team structure which is capable of having this amount of students?