query: SELECT DISTINCT ?item ?itemLabel ?start ?end ?district ?districtLabel ?group ?groupLabel WHERE { 
    ?item p:P39 ?mem .
    ?mem ps:P39 wd:Q654291 ; pq:P2937 wd:Q28976095 . 
    OPTIONAL { ?mem pq:P580  ?start }
    OPTIONAL { ?mem pq:P582  ?end }
    OPTIONAL { ?mem pq:P768  ?district }
    OPTIONAL { ?mem pq:P4100 ?group }
    SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
  }