Find nth row and continue calculation

[QSense]

Hello ,

I have a problem. I have a straight table and column names are 

Month,ID,INPUT,OUTPUT,ONHAND

Onhand formula is : peek(Onhand,-1) + input - output.

As you see there is no 202007 value so 202008 onhand value is wrong.

It must be 2 then after 202008 value's must be according to formula ;

202009      0

202010      -3

202011      -5

202012      5

202101      -2

[Channa]

can you share little more sample data

[QSense]

202003	4013382-682P02P	6	9	-3
202004	4013382-682P02P	10	3	4
202005	4013382-682P02P	6	6	4
202006	4013382-682P02P	4	6	2
202008	4013382-682P02P	5	5	0
202009	4013382-682P02P	0	2	-2
202010	4013382-682P02P	0	3	-5
202011	4013382-682P02P	0	2	-7
202012	4013382-682P02P	10	0	3
202101	4013382-682P02P	0	7	-4
202102	4013382-682P02P	0	3	-7