Replicating excel formula | precedent referencing

let
    Source = your_source_table,
    data = List.Buffer(Source[Total engine hours]),
    max_count = List.Count(data),
    pulse = 
        List.Generate(
            () => [i = 0, p = 0],
            (x) => x[i] < max_count,
            (x) => [i = x[i] + 1, p = if (data{i} >= data{x[i]}) then x[p] + data{i} - data{x[i]} else x[p]],
            (x) => x[p]
        ),
    out = Table.FromColumns(Table.ToColumns(Source) & {pulse}, Table.ColumnNames(Source) & {"Pulse"})
in
    out