Создать функцию с именем fnAddRunningSum
(MyTable as table) as table =>
//see: https://community.powerbi.com/t5/Desktop/How-to-do-a-running-Sum-by-group-in-Power-Query/td-p/290123
let Source = Table.Buffer(MyTable),
TableType = Value.Type(Table.AddColumn(Source, "Running Sum", each null, type number)),
Cumulative = List.Accumulate(Source[Count],{},(cumulative,amount) => cumulative & {List.Last(cumulative, 0) + amount}),
AddedRunningSum = Table.FromColumns(Table.ToColumns(Source)&{Cumulative},TableType)
in AddedRunningSum
затем создайте запрос
let Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
#"Grouped" = Table.Group(Source, {"ClosedFiscalYear"}, {{"AllData", fnAddRunningSum}}),
#"Expanded AllData" = Table.ExpandTableColumn(#"Grouped", "AllData", {"ClosedMonth", "Count", "Index", "Running Sum"}, {"ClosedMonth", "Count", "Index", "Running Sum"})
in #"Expanded AllData"