Incorrect sales field in the customers section

[kse]

Incorrect sales field in the customers section:

I see the sum of all purchases made in general, and not by this particular client.

In my store I have bought 2 people:

person 1 = € 75.68
person 2 = € 75.68

I get in the clients section, in the field "sales" the sum of the two. You would have to put only the total of what this person has bought.

Why is this happening? Can somebody help me ?

Thank you