How to calculate the difference of two cells from a table?

[cperazza]

So it seems that I'm stuck with this simple challenge:

Every first day of the month, our system records the number of members for the previous month and records it as a table (see example below).
I would like to be able to calculate the difference between the most recent period (highlighted in green) vs the oldest period (highlighted in yellow).
Using the table below as an example, the result should be 20 (and I would like to call it "Acquisition Rate").

There's no workflow at this stage, the table below is coming from my DB as it is.

Any ideas?

TIA

[Qiu]

@cperazza 
We can do the Sort accendinly by the  "Acquisition Rate" then use the Sample to acquire first row (oldest) and last row (most recent) then do a compare.

[JarekSkudrzyk]

@cperazza you may also want to sort by "changed_date" rather than "Acquisition Rate" - to cover the case when the number of accounts drops.

[Sebastiaandb · Accepted solution]

Hi @cperazza,

Like @Qiu said :-). Hereby the solution so you don't have to solve the puzzle anymore :-).

Greetings,

Seb

[cperazza]

Hi Seb,

Many thanks for your help. I'm trying to open this file but it doesn't work.
Do I have to change anything on it to open on Designer?

Cheers

[cperazza]

Many thanks, Qiu!

You pointed me in the right direction