Distributing 1 amount over different months

PDE 

I have also tried a soluton, please check. Two calculated columns need to be added to your table:

Allocation = 
var __amount = 1000
var __monthly = 99
var __cumm = __monthly + __amount -  SUMX( FILTER( 'Table' , 'Table'[Month] <= EARLIER( 'Table'[Month] ) ),	__monthly)
var __val = MAX( min( __monthly , __cumm ) ,0)
    return
	__val

Running Total = 
IF( 'Table'[Allocation] > 0 ,  SUMX( FILTER( 'Table' , 'Table'[Month] <= EARLIER( 'Table'[Month] ) ) , [Allocation] ))

Allocation = 
MAX(
    MIN(
        99,
        1000 - COUNTROWS( WINDOW( 1, ABS, -1, REL, ALLSELECTED( data[Period] ) ) ) * 99
    ),
    0
)

RT = 
MIN(
    COUNTROWS( WINDOW( 1, ABS, 0, REL, ALLSELECTED( data[Period] ) ) ) * 99,
    1000
)