query: SELECT DISTINCT ?item ?itemLabel ?membershipLabel ?presumedLabel ?positionStatement ?presumed
  WHERE {
   ?membership wdt:P279 wd:Q16707842 . 
   ?item p:P39 ?positionStatement . ?positionStatement ps:P39 ?membership .
   filter not exists { ?positionStatement pq:P2937 ?term . }
   ?membership wdt:P2937 ?presumed .
   ?membership wdt:P571 ?start . 
   # FILTER (?start >= "1935-01-01T00:00:00Z"^^xsd:dateTime) .
   SERVICE wikibase:label { bd:serviceParam wikibase:language 'en' } 
  }
  