See how many new customers in janurary have returned in february

[Anonymous]

What i want is a Matrix where i have First delivery on Rows, Date on Columns and measure Number of customers as Values
We have some discount codes that we give to new customers when they do their first delivery. 
And i want to follow those customers, for example if i pick in Slicer discount code = New2018
I get for example in january we have 1300 customers that used the code as their first purchase and i want to see how many of them have have made at least 1 purchase in february and so on.

Right now i export to excel all the customer ID:s and then use as source and create an realtion with other tables and to select just those customers, but i dont want to do this manually everytime my colleagues are asking for this information.

Measure and columns im using are
Measure Number of customers = DISTINCTCOUNT('Order'[MemberId])
Calculated column First delivery = RELATED('Member'[First delivery].[Date])
Column Date from date table
And column Discount code as Slicer

I want it to look something like this as you see 1300 new customers in january and 293 returned in febrary and ofcourse we are just some days into march so thats why that number is so low.
And i want to be able to to so with different discount codes

Year | 2018
Year | January | February | March
2018
January | 1300 | 293 | 41
(Srry for not insterting a picture, dont know how to do it)
thanks in advance

[v-yuezhe-msft]

@Anonymous,

Could you please share sample data of your table?

Regards,
Lydia

[Anonymous]

@v-yuezhe-msft

https://drive.google.com/open?id=1gGV0LNporRDhtzBUj7UkqqBtyRcfE7UR

First picture:

Not filtering anything with my discount code slicer

Second

Im marking Those customers that use discount code NEW.

Third:

Same as second picture but now i marked the 18 first member ids to the right to lock them and follow them on the Matrix

Fourth:

I have released the slicer value NEW so im following those 18 members i marked in third picture.

Problem here is i cant sit and mark every member id becuase its over 1000.(This sample) but i have over 400.000 member id to work with.

This is for my company are giving out some discount codes and we want to follow those customers(right now new customers) and see if we are geting loyal customers or only customers that hunt for discounts.

Matrix
Rows im using "First delivery" column in table "Member" and im only using Year and Month.

Columns im using "Date" column in table "Date" and im only using Year and Month.

Values im using an Measure Churn % = [Number of customers] / CALCULATE([Number of customers] ; FILTER(ALLSELECTED('Date');'Date'[Date]<=MAX('Date'[Date])))

Measure that im not using in the Matrix but in my Churn measure: Number of customers = DISTINCTCOUNT('Order'[MemberId])