What is {population} of {Zaragoza} that is {determination method} is {register office} ?
What is the population of Zaragoza whose determination method is register office?
SELECT ?obj WHERE { wd:Q10305 p:P1082 ?s . ?s ps:P1082 ?obj . ?s pq:P459 wd:Q745221 }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q10305> .
?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> ?obj .
?statement <http://www.wikidata.org/entity/P459> <http://wikidata.dbpedia.org/resource/Q745221>
} 

According to the registered office's determination method, what is Zaragoza's population?