Сalculate Avg Number of employees in next month

[ExMachina]

Good everyone.

I want to calculate the average number of employees in the company in such a way that the average value of the previous month+the current month divided by two is recorded in each current month.
For example,

Months      | Quantity
January     | 45
February   | 48
March         | 50
April            | 49

As a result, the Headcount will be the following:

                        |  January    |    February      |          March       |        April
Headcount |         45         |   (45+48)/2      |       (48+50)/2    |    (50+49)/2

Tell me how you can implement it and where it is better to make the calculation: in the download script or on the dashboard?

[jochem_zw]

you can do it both, but in frontend the expression would be something like this:

if(Months='January'

,sum(Quantity)

,(above(sum(Quantity))+sum(Quantity))/2)

[ExMachina]

Thanks Jochem_zw for your answer, but in this case, the above function hides the first value, which is not very suitable for solving the problem

Why I cannot  use the similar condition:

If(Month(Date_Per) = 'Jan' and Year(Date_Per)='2019', Count(Distinct FIO),
       If(Date_Per> AddMonths(Date_Per,-1) and MonthName(Date_Per, 'MMM-YYYY')<>'Jan-2019'
            (Count(Distinct FIO)+Count(Distinct {<Month={'$(=Month(AddMonths(Date_Per,-1)))'}>} FIO))/2

          )

   )

[jcdatasax]

Have you tried the Peek() function?  

‘(Peek(quantity ) + quantity) / 2 AS Quantity‘  (in the script). You can also use peek() in the front end in a simple expression. 

[jcdatasax]

... to be clear, you’d use the peek() function as the second part of the IF() statement.