query: embed.html#select ?constituency ?item ?name ?group ?start ?end where {
  ?item p:P39 ?z. ?z pq:P768 wd:Q3334702.
  wd:Q3334702 rdfs:label ?constituency. filter(lang(?constituency)="en")
  ?item rdfs:label ?name. filter(lang(?name)="en")
  optional {?z pq:P4100 ?g. ?g rdfs:label ?group. filter(lang(?group)="en")}  
  optional {?z pq:P580 ?i. bind(year(?i) as ?start)}
  optional {?z pq:P582 ?j. bind(year(?j) as ?end)}
  } order by ?start ?i