Size Distribution of Inner London 2 Bed Flats

I have been looking at 2 bed flats on spareroom and often they have one good sized bedroom with good storage, but the other room is quite small and has poor storage.

I used to share in a 900 sqft flat, which at the time I thought was quite small, but I cannot find anything on spareroom this size really. I am wondering now how rare this is.

I can see this online, https://www.plumplot.co.uk/London-flat-features.html, but it doesn't really answer how 2 bed flats are distributed in size.

I can see also on Rightmove that many 2 beds are 700 sqft and under.

What's a large, medium and small 2 bed flat in Zones 1 and 2?