private function createChartData(array $places): array
    {
        $data = [
            [
                I18N::translate('Country'),
                I18N::translate('Total'),
            ],
        ];

        // webtrees uses 3 letter country codes and localised country names, but google uses 2 letter codes.
        foreach ($places as $country => $count) {
            $data[] = [
                [
                    'v' => $country,
                    'f' => $this->country_service->mapTwoLetterToName($country),
                ],
                $count
            ];
        }

        return $data;
    }