I wish I could answer that, but we've never made public any popularity statistics that are even slightly reliable. This might be changed some time, but nobody knows when. So, what little I know is what I've seen, and others will have seen different things.
I did a couple of months of relief teaching at a local girls' high school last year and nothing really stood out: plenty of
Emma and
Caitlyn people,
Taylor and
Tayla in the same class,
Sophia ... pretty mainstream.