+    {

+        // Tom's algorithm.

+        $national_events = $this->batch->events;

+        $national_attendance = 0;

+        foreach($national_events as $event){

+            if($event->allow_registrations){

+                $national_attendance += $event->registrations->count();

+            }

+        }

+        $national_average = $national_attendance / $national_events->count();

+

+        $regional_events = DB::table('regions')->where('time_zone', '=', 'timezone')->get();

+        $regional_attendance = 0;

+        foreach($regional_events as $event){

+            if($event->allow_registrations){

+                $regional_attendance += $event->registrations->count();

+            }

+        }

+        $regional_average = $regional_attendance / $regional_events->count();

+        

+        $local_events = DB::table('events')->where('region_id', '=', $this->region_id)->get();;

+        $local_attendance = 0;

+        $local_events_count = 0;

+        foreach($local_events as $event){

+			if($event->allow_registration && $event->region == $this->region){

+                $local_attendance += $event->registrations->count();

+                $local_events_count += 1;

+            }

+        }

+        $local_average = $local_attendance / $local_events_count;

+

+        return round(($national_average + (2 * $regional_average) + (3 * $local_average)) / 6);