Calculate Moving range ( subtract previous row value from earlier row)

Hi Anonymous ,

1. Insert an index column in power query as below.

M code as below.

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WKjYwKDXIzDMyyErMU9JRMjZVitVBiBpCRE0MUESNoKJGSrGxAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [key = _t, result = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"key", type text}, {"result", Int64.Type}}),
    #"Added Index" = Table.AddIndexColumn(#"Changed Type", "Index", 1, 1)
in
    #"Added Index"

2. Create the measure to get the exceoted result.

Measure = var change =  CALCULATE(SUM(Table1[result]),FILTER(ALL(Table1),Table1[Index]=MAX(Table1[Index])-1))
return
IF(ISBLANK(change),BLANK(),MAX(Table1[result])-change)

Pbix as attached.

Regards,

Frank