what is the {proportion} for {Japan} has {ethnic group} as {Japanese people} ?
What population of Japan is considered ethnic Japanese?
How many people in Japan are considered ethnic Japanese?
SELECT ?r WHERE { resource:Japan property:ethnic_group ?d . ?d property:ethnic_group resource:Japanese_people . ?d property:proportion ?r }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q17> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P172> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q161652> .
?statement <http://www.wikidata.org/entity/P1107> ?value. 
} 

SELECT ?value WHERE { wd:Q17 p:P172 ?s . ?s ps:P172 wd:Q161652 . ?s pq:P1107 ?value}