what is the {point in time} for {Basel} has {population} as {173619.0} ?
When was Basel's population 173619?
When did Basel's population reach 173619?
SELECT ?w WHERE { ?v property:point_in_time ?w . ?v property:population ?c . resource:Basel property:population ?v . FILTER ( ?c = 173619.0 ) }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q78> .
?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> <173619.0> .
?statement <http://www.wikidata.org/entity/P585> ?value. 
} 

SELECT ?value WHERE { wd:Q78 p:P1082 ?s . ?s ps:P1082 ?x filter(contains(?x , '173619.0')) . ?s pq:P585 ?value}