I had my Pfizer done there yesterday and it certainly wasn't over 60's if anything the opposite. A few pregnant women and Thai's having it done also.
It's a long process as someone suggested up-thread.
My next one is 16 September so I'll plan it from my observation. They are setting people in time groups strictly every hour. If you get there 1 hr early you'll be shuffled to a waiting area until your time has arrived.
Observing yesterday's plan I noticed that around 4pm the waiting was minimal. I plan on arriving at 3:30 pm for a 2pm appointment.