When you divide two integers, the result will always be truncated. If you want to round the result instead, then one of the values needs to be a floating-point type.
ROUND(CONVERT(real, SUM([turnoverSM (%)])) / COUNT(DISTRICT), 0)
ROUND (Transact-SQL) | Microsoft Docs[
^]
Also, in case you haven't realised it yet, it's an
extremely bad idea for table or column names to contain spaces or other special characters. If possible, you should redesign your database to rename the columns so that they only use alphanumeric characters.