public function split()
    {
        return [
            'outward'     => $this->outward(),
            'inward'      => $this->inward(),
            'area'        => $this->area(),
            'district'    => $this->district(),
            'subdistrict' => $this->subdistrict(),
            'sector'      => $this->sector(),
            'unit'        => $this->unit(),
            'normalise'   => $this->normalise(),
        ];
    }