Year and month problem

Hi,

I am trying to put together a view that resembles the image on the project page. But what I am trying to do is to output a list that shows only a year and months with a post count like this:

2016

february (6)
april (2)
....

2017
january (2)
december (10)

(months and post count are merely examples in this issue)

At the moment I cloned the view and used content: created year & content: created month as contextual filter.

But the output gives me only the year with a post count: 2017 (6)

Any help in solving this?