Running Total for each Group / ID

[ompowerbi]

Hi, I am trying to create a running total in my table that only does the running total for each respective Group / ID. An example of my table is below. 

ID	Number	Date
Apple	20	01/01/2023
Apple	-30	06/01/2023
Apple	-40	11/01/2023
Apple	20	16/01/2023
Banana	10	02/12/2022
Banana	10	07/12/2022
Banana	-40	12/12/2022
Banana	10	17/12/2022
Banana	-50	22/12/2022
Orange	-80	09/02/2022
Orange	10	21/02/2022
Orange	10	05/03/2022
Orange	20	17/03/2022
Orange	10	29/03/2022

The result would ideally look like this:

ID	Number	Date	Running total per group
Apple	20	01/01/2023	20
Apple	-30	06/01/2023	-10
Apple	-40	11/01/2023	-50
Apple	20	16/01/2023	-30
Banana	10	02/12/2022	10
Banana	10	07/12/2022	20
Banana	-40	12/12/2022	-20
Banana	10	17/12/2022	-10
Banana	-50	22/12/2022	-60
Orange	-80	09/02/2022	-80
Orange	10	21/02/2022	-70
Orange	10	05/03/2022	-60
Orange	20	17/03/2022	-40
Orange	10	29/03/2022	-30

I have been using these formulas in power query:
Sum by group:

= Table.AddColumn(#"Added Custom", "Custom.1", each let _Group = [ID] in
List.Sum(
Table.SelectRows(#"Added Custom", each [ID] = _Group)[Number]))


Running Total:
= Table.AddColumn(#"Added Index", "Custom", each List.Sum(List.FirstN(#"Added Index"[Number],[Index])))

I have been trying to combine these two but I cannot seem to get them to work together, does anyone have any suggestions. (I am fairly new to power query and M code). 

Thank you 

[Vijay_A_Verma · Accepted solution]

Use this. Replace ??? appropriately

let
    Source = ???
    BuffNumberList = Source[Number],
    BuffIDList = Source[ID],
    GenListOfRunningTotal = List.Generate(()=>[x=BuffNumberList{0},y=0], each [y]<List.Count(BuffNumberList), each [y=[y]+1, x=if BuffIDList{y} = BuffIDList{[y]} then [x]+BuffNumberList{y} else BuffNumberList{y}], each [x]),
    Result = Table.FromColumns(Table.ToColumns(Source) & {GenListOfRunningTotal},Table.ColumnNames(Source)&{"Running total per group"})
    in
    Result

[ompowerbi]

Thank you for the response, this works great. If you don't mind, I had come up with something sort of similar as a blank query. 

(values as list, ID as list) as list=>
let
RT =
List.Generate(
()=>[RT = values{0},counter = 1],
each [counter]-1 < List.Count(values),
each (if ID{[counter]-1}=ID{[counter]}
then [RT = [RT]+values{[counter]},counter=[counter]+1]
else [RT = values{[counter]},counter=[counter]+1]),
each [RT])
in
RT

However, on this line "each [counter]-1 < List.Count(values)," I get the error message: 'An error occurred in the ‘’ query. Expression.Error: There weren't enough elements in the enumeration to complete the operation.
Details: [List]', and another line is added to the table just saying error for each column.

If I change the line to: " each [counter] < List.Count(values)," then the last value in the RT (running total) column is null. I am not sure of a way around this, do you have any suggestions please?

[ompowerbi]

Thank you for the response, this works great. If you don't mind, I had come up with something sort of similar as a blank query. 

(values as list, ID as list) as list=>
let
RT =
List.Generate(
()=>[RT = values{0},counter = 1],
each [counter]-1 < List.Count(values),
each (if ID{[counter]-1}=ID{[counter]}
then [RT = [RT]+values{[counter]},counter=[counter]+1]
else [RT = values{[counter]},counter=[counter]+1]),
each [RT])
in
RT

However, on this line "each [counter]-1 < List.Count(values)," I get the error message: 'An error occurred in the ‘’ query. Expression.Error: There weren't enough elements in the enumeration to complete the operation.
Details: [List]', and another line is added to the table just saying error for each column.

If I change the line to: " each [counter] < List.Count(values)," then the last value in the RT (running total) column is null. I am not sure of a way around this, do you have any suggestions please?