That’s a huge amount of people who didn’t answer. Phones are basically worthless to get ahold of people — I called about 40 students last spring for interviews and got only one answer, myself.
I've noticed some people saying "kids don't pick up phones anymore" and really, no, we don't. There's more efficient and reliable communication modes available. If I could pay for a sperate set of phone numbers that were text-only, I would have that instead.
Kids? Hell, I'm 47 and that's my policy as well. I basically don't answer unsolicited phone calls unless it's my dad or one of a very small number of close friends or family members. And honestly, even that's not guarantee that I will pick up at times.
Haven't been asked/invited to call?