Centre renovated in old mansion that's one in a hundred (10)
I believe the answer is:
percentile
'one in a hundred' is the definition.
The definition suggests a singular noun which matches the answer.
'centre renovated in old mansion' is the wordplay.
'renovated' indicates anagramming the letters.
'in' indicates putting letters inside.
'old mansion' becomes 'pile' (pile can mean a large building. I am not sure about the 'old' bit.).
'centre' with letters rearranged gives 'ercent'.
'ercent' put within 'pile' is 'PERCENTILE'.
'that's' is the link.
Can you help me to learn more?
(Another definition for percentile that I've seen is " Any of the 99 numbered points that divide a set into 100 equal parts".)