query: PREFIX wd: <http://www.wikidata.org/entity/>
  PREFIX wdt: <http://www.wikidata.org/prop/direct/>
  PREFIX wikibase: <http://wikiba.se/ontology#>
  PREFIX p: <http://www.wikidata.org/prop/>
  PREFIX v: <http://www.wikidata.org/prop/statement/>
  PREFIX q: <http://www.wikidata.org/prop/qualifier/>
  PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
  
  SELECT ?nb ?person ?personLabel ?start ?end WHERE
  {
     ?person p:P39 ?position_held_statement .
     ?position_held_statement v:P39 wd:Q3773745 . #position held: governor of Vermont
     ?position_held_statement q:P580 ?start . # only with start date
     OPTIONAL { ?position_held_statement q:P582 ?end } .
     OPTIONAL { ?position_held_statement q:P1545 ?nb } .
     ?person wdt:P31 wd:Q5 .   			#only real people
    
    OPTIONAL { 
       ?person rdfs:label ?personLabel filter (lang(?personLabel) = "en"). 
     }
  }
  ORDER BY ?start
  
  