what is the {end time} for {William Blackstone} has {position held} as {Member of Parliament in the United Kingdom} ?
When did William Blackstone end his time as a Member of the Parliament of the United Kingdom?
SELECT ?value WHERE { wd:Q332449 p:P39 ?s . ?s ps:P39 wd:Q16707842 . ?s pq:P582 ?value}
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q332449> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P39> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q16707842> .
?statement <http://www.wikidata.org/entity/P582> ?value. 
} 

on what date did William Blackstone end his time as a Member of the Parliament of the United Kingdom?