query: SELECT ?item ?inv ?sitter WHERE {
    ?item wdt:P195 wd:Q238587 .
    ?item wdt:P31 wd:Q3305213 .
    OPTIONAL {   ?item p:P217 ?invstatement .
    ?invstatement ps:P217 ?inv .
    ?invstatement pq:P195 wd:Q238587 . }
    OPTIONAL { ?item wdt:P180 ?sitter .
              ?sitter wdt:P31 wd:Q5 }
    } ORDER BY xsd:integer(REPLACE(?inv, "^(NPG )L?(\\d+)([^\\d].*)?$", "$2"))
  LIMIT 4000