query: SELECT ?item ?itemLabel ?person ?personLabel ?start
  WHERE 
  {
    ?item wdt:P361 wd:Q2579210.
    OPTIONAL { 
      ?person p:P39 ?mandate .
      ?mandate ps:P39 ?item ; pq:P580 ?start .
      MINUS { ?mandate pq:P582 ?end }
      MINUS { ?item wdt:P576 [] }
    }
    SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
  }