Q:

"top x% this month" appears lower even though my rank is higher

I was active mainly in Stack Overflow but recently joined the beta Arabic.SE.
In Arabic.SE I am holding the 1st rank monthly, however it shows in my profile that I am in the top 8% this month:

In the other hand, on SO, it shows I am in 2% this month:

How is that possible? Shouldn't it be a better percentage where my rank is higher?

A:

For Stack Overflow this is the calculation:

Your rank: 3,118
Users with reputation activity: 158,471

3,118 / 158,471 = 1,96%

And Arabic Language:

Your rank: 1
Users with reputation activity: 13

1 / 13 = 7,69%

The point in this is: there are much less active users on Arabic than on SO, so your top % will be lower on Arabic, even when you are first.

