                     if row == 0, let strip = fissionsAlphaWellPerAct.itemFor(side: .back)?.strip1_N {
                         field = String(format: "%d", strip)
                     }
+                case keyColumnNeutronsAverageTime:
+                    if row == 0 {
+                        let count = neutronsPerAct.count
+                        if count > 0 {
+                            let average = Float(neutronsPerAct.reduce(0, +))/Float(count)
+                            field = String(format: "%.1f", average)
+                        } else {
+                            field = "0"
+                        }
+                    }
                 case keyColumnNeutrons:
                     if row == 0 {
-                        field = String(format: "%llu", neutronsSummPerAct)
+                        field = String(format: "%llu", neutronsPerAct.count)
                     }
                 case keyColumnNeutrons_N:
                     if row == 0 {

    fileprivate var keyColumnStartWellBackMarker = "*WellBackMarker"
    fileprivate var keyColumnStartWellBackPosition = "*WellBackPos"
    fileprivate var keyColumnStartWellBackStrip = "Strip(*WellBack)"
    fileprivate var keyColumnNeutrons = "Neutrons"
    fileprivate var keyColumnNeutrons_N = "N1...N4"
    fileprivate var keyColumnNeutronsBackward = "Neutrons(Backward)"

     Summar multiplicity of neutrons calculation over all files
     */
    fileprivate func updateNeutronsMultiplicity() {
        let key = neutronsPerAct.count
        var summ = neutronsMultiplicityTotal[Int(key)] ?? 0
        summ += 1 // One event for all neutrons in one act of fission
        neutronsMultiplicityTotal[Int(key)] = summ
