Fix booth recounts poll stats discrepancies

Due to technical issues, sometimes users voted in booths and their vote
couldn't be added to the database. So we're including them in the users
with no demographic data.

app/models/poll/stats.rb

@@ -89,6 +89,10 @@ class Poll::Stats
     end
   end
 
+  def total_no_demographic_data
+    super + total_unregistered_booth
+  end
+
   private
 
     def participant_ids
@@ -103,6 +107,14 @@ class Poll::Stats
       @recounts ||= poll.recounts
     end
 
+    def total_registered_booth
+      voters.where(origin: "booth").count
+    end
+
+    def total_unregistered_booth
+      [total_participants_booth - total_registered_booth, 0].max
+    end
+
     stats_cache(*stats_methods)
 
     def stats_cache(key, &block)