What is {population} of {Bonn} that is {point in time} is {1970-12-31} ?
What was Bonn's population on December 31st, 1970?
What was the population of Bonn as of December 31st, 1970?
SELECT ?j WHERE { ?m property:point_in_time ?b . ?m property:population ?j . resource:Bonn property:population ?m . FILTER ( CONTAINS ( YEAR ( ?b ) , '1970' ) ) }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q586> .
?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/P585> <1970-12-31>
} 

SELECT ?obj WHERE { wd:Q586 p:P1082 ?s . ?s ps:P1082 ?obj . ?s pq:P585 ?x filter(contains(YEAR(?x),'1970')) }