Question: When did Madrid have a population of 3.21327e+06?
Paraphrase: In what year did Madrid have a population of 3.21327e+06?
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q2807 p:P1082 ?s . ?s ps:P1082 ?x filter(contains(?x , '3.21327e+06')) . ?s pq:P585 ?value}