The ratio ranges from as little as 3 teachers for each administrative or managerial school staff member in New Zealand to 20 in Austria …

„According to lower secondary principals’ reports, there are on average seven teachers for each administrative or managerial school staff member across the OECD, but the ratio ranges from as little as 3 in New Zealand to 20 in Austria.“
OECD (Hrsg.), Working and Learning Together (2019), S. 173.