what is the {determination method} for {Bilbao} has {population} as {351629.0} ?
What is the determination method that Bilbao has the population of 351629.0?
SELECT ?value WHERE { wd:Q8692 p:P1082 ?s . ?s ps:P1082 ?x filter(contains(?x,'351629.0')) . ?s pq:P459 ?value}
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q8692> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1082> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <351629.0> .
?statement <http://www.wikidata.org/entity/P459> ?value. 
} 

By what method was the population of 351629.0, in Bilbao, determined?