Disaggregated stats wrong total

src/formpack/schema/fields.py

@@ -224,8 +224,18 @@ def get_disaggregated_stats(self, metrics, top_splitters,
         not_provided = 0
         provided = 0
         for val, counter in metrics.items():
-            not_provided += counter.pop(None, 0)
-            provided += counter.pop('__submissions__', 0)
+            none_submissions = counter.pop(None, 0)
+            not_provided += none_submissions
+            # `counter[None]` corresponds to submissions with no values for current field (`self`)
+            # If `val` is None, some submissions don't have any values for the `splitted_by_field`.
+            # We should consider all these submissions as `not_provided`
+            if val is None:
+                not_provided += sum(counter.values())
+            else:
+                # `counter['__submissions__'] contains the count of all submissions,
+                # including those where no response was provided.
+                # We need to substract all submissions with no response
+                provided += counter.pop('__submissions__', 0) - none_submissions
 
         return {
             'total_count': not_provided + provided,