Legends on 2 different Saturday nights

First Saturday I arrived about 6:30pm and there were about 6 very average girls present. As The evening progressed more and more ladies arrived, by 10 pm there were about 25 dancers and more kept arriving.

The second Saturday I showed up at 8:30 pm. Lots of dancers present and more Rriving even as late as 11pm.

Guidance: don't get there too early.