diff --git a/EvoCalculator.Core.Calculation/Columns/SumColumn.cs b/EvoCalculator.Core.Calculation/Columns/SumColumn.cs
index 05cb037..d21bfd3 100644
--- a/EvoCalculator.Core.Calculation/Columns/SumColumn.cs
+++ b/EvoCalculator.Core.Calculation/Columns/SumColumn.cs
@@ -53,14 +53,16 @@ namespace EvoCalculator.Core.Calculation.Columns
             var DIFFICULT_CASE = _percentPaymentColumn.Values.Take(_percentPaymentColumn.Values.Length - 1)
                 .Any(x => x < 3 && x > 0);
 
+            var NUMBER_OF_RATHER_50 = _percentPaymentColumn.Values
+                .Skip(2)
+                .Take(_percentPaymentColumn.Values.Length - 1)
+                .Where(x => x >= 10).ToArray().Length;
+
             var goalSeek = new GoalSeek(this);
             goalSeek.SeekResult(requiredValue,
                 new GoalSeekOptions(
                     startingStabPoint:
-                    (_postValues.BaseCost.Value - _preparedValues.FirstPaymentSum) /
-                    (_preparedValues.Nmper - 3) * (DIFFICULT_CASE
-                        ? 0.1m
-                        : 1m)
+                    (_postValues.BaseCost.Value - _preparedValues.FirstPaymentSum) / NUMBER_OF_RATHER_50
                     , maximumAttempts: 1000
                     , initialTineSpacing: DIFFICULT_CASE ? 10000m : 1000m
                     // , focusPercentage: 50