foreach ($this->startStop(180, 'minute', 'Y-m-d H:i:s') as $x => $info) { // D M j
            list($start, $stop) = $info;
            $this->db->execute($stmt, array($start, $stop));
            list($loaded, $server) = $this->db->fetch($stmt);
            $data[] = '{x:"'.$x.'", loaded:'.round($loaded, 2).', server:'.round($server, 2).'}';