$cursor = $reviews->find(
                array(
                    'date'
                    => array(
                        '$gte' => new MongoDate(mktime(0, 0, 0, 1, 1, 1970)), '$lte' => $this->endDate
                    ),
                    'type' => 'scoreboard',
                    'period' => 'day'
                ), array('aggregates.1' => 1)
            );