How to create tables correctly?

Question

Database design

Look, we have, let's say, a group VK = ABC.
And there is an array of subscribers and they have the following parameters:
1. Gender
2. Age
3. City

I sort them out and save them accordingly, how it will be more correct to design the tables so that in the future you can find out the following information: In the ABC group in the city of Moscow
, 20 years : 15m/23f
21 years old: 19m/13f

Well, it's the same with other cities.
Krch so that you can see the sex ratio at a particular age and city
. Further, with another group, DEF is already allowed there