function export(array $data, $sheet) {
		$groups = array();

		// split full list into separate files
		// reading them back in is a lot faster this way
		foreach ($data as $id => $array) {
			$key = floor($id / 1000000);
			$groups[$key][$id] = $array['name'].'.'.$array['sheet'];
		}

		$ext = $this->encoder->name();
		foreach ($groups as $key => $array) {
			$idx = sprintf("%02x", $key);
			$filename = "{$this->path}/{$sheet}-{$idx}.{$ext}";
			file_put_contents($filename, $this->encoder->encode($array));
		}
	}