diff --git a/libraries/KustoLoco.Core/Evaluation/SummaryKey.cs b/libraries/KustoLoco.Core/Evaluation/SummaryKey.cs
index 2c3468c..9f5c29a 100644
--- a/libraries/KustoLoco.Core/Evaluation/SummaryKey.cs
+++ b/libraries/KustoLoco.Core/Evaluation/SummaryKey.cs
@@ -10,6 +10,11 @@ public record struct SummaryKey
     private object? O2;
     private object? O3;
     private object? O4;
+    private object? O5;
+    private object? O6;
+    private object? O7;
+    private object? O8;
+    private object? O9;
 
     public SummaryKey()
     {
@@ -22,20 +27,57 @@ public SummaryKey(object?[] objects)
             Set(i, objects[i]);
         }
     }
-
+    /// <summary>
+    /// Sets a value in the key
+    /// </summary>
+    /// <remarks>
+    /// Use with care.  SummaryKey is a struct so
+    /// Set only works locally or in preparation for passing
+    /// the record to a method.
+    /// </remarks>
     public void Set(int i, object? o)
     {
         if (i >= num)
             num = i + 1;
-        if (i == 0) O0 = o;
-        if (i == 1) O1 = o;
-        if (i == 2) O2 = o;
-        if (i == 3) O3 = o;
-        if (i == 4) O4 = o;
-        if (i > 4)
-            throw new NotImplementedException("summarize limited to 5 vals");
+        switch (i)
+        {
+            case 0:
+                O0 = o;
+                break;
+            case 1:
+                O1 = o;
+                break;
+            case 2:
+                O2 = o;
+                break;
+            case 3:
+                O3 = o;
+                break;
+            case 4:
+                O4 = o;
+                break;
+            case 5:
+                O5 = o;
+                break;
+            case 6:
+                O6 = o;
+                break;
+            case 7:
+                O7 = o;
+                break;
+            case 8:
+                O8 = o;
+                break;
+            case 9:
+                O9 = o;
+                break;
+            case > 9:
+                throw new NotImplementedException("summarize operator is limited to 10 properties");
+        }
     }
-
+    /// <summary>
+    /// Creates an array of the values in the key
+    /// </summary>
     public object?[] GetArray()
     {
         var ret = new object?[num];
@@ -44,6 +86,11 @@ public void Set(int i, object? o)
         if (num > 2) ret[2] = O2;
         if (num > 3) ret[3] = O3;
         if (num > 4) ret[4] = O4;
+        if (num > 5) ret[5] = O5;
+        if (num > 6) ret[6] = O6;
+        if (num > 7) ret[7] = O7;
+        if (num > 8) ret[8] = O8;
+        if (num > 9) ret[9] = O9;
         return ret;
     }
-}
\ No newline at end of file
+}
diff --git a/libraries/KustoLoco.Core/Evaluation/TreeEvaluator.NpmSummarySet.cs b/libraries/KustoLoco.Core/Evaluation/TreeEvaluator.NpmSummarySet.cs
deleted file mode 100644
index ffab10a..0000000
--- a/libraries/KustoLoco.Core/Evaluation/TreeEvaluator.NpmSummarySet.cs
+++ /dev/null
@@ -1,5 +0,0 @@
-namespace KustoLoco.Core.Evaluation;
-
-internal partial class TreeEvaluator
-{
-}
\ No newline at end of file