List.Generate to calculate column based on the previous row value of the Same Column

Hi DSR, check this:

Output

let
    Source = Table.FromRows( {
        {"A", 0, "Yr00", 0, 2, 0, 0},
        {"A", 1, "Yr01", 0, 2, 1, 1},
        {"A", 2, "Yr02", 1, 2, 2, 1},
        {"A", 3, "Yr03", 1, 2, 3, 1},
        {"A", 4, "Yr04", 1, 2, 4, 0},
        {"A", 5, "Yr05", 0, 2, 5, 1},
        {"A", 6, "Yr06", 1, 2, 6, 0},
        {"A", 7, "Yr07", 0, 2, 7, 0},
        {"A", 8, "Yr08", 0, 2, 8, 0},
        {"A", 9, "Yr09", 0, 2, 9, 0},
        {"A", 10, "Yr10", 0, 2, 10, 0} },
        {"Case.CC.EEName", "PeriodNo", "Yr", "NoEE.inPrvPrd", "Yr Move Out", "Index.inGrp", "NoEE"} ),
    L = List.Buffer(Table.ToRows(Table.SelectColumns(Source,{"NoEE", "Index.inGrp", "Yr Move Out"}))),
    Gen = List.Skip(List.Generate(
        ()=> [ x = -1],
        each [x] < List.Count(L),
        each [ x = [x]+1, y = L{x},
               z = if (y{0}??0) = 0 then null
                   else if (y{1}??0) = 0 then null
                   else if ([z]??0) = 0 then 1
                   else if [z] = y{2} then y{0}
                   else [z] +1 ],
        each [z] )),
    Merged = Table.FromColumns(Table.ToColumns(Source) & {Gen}, Value.Type(Table.FirstN(Source, 0) & #table(type table[Answer=Int64.Type], {})))
in
    Merged