query: # properties with most “no value” statements/qualifiers/references (truthy statements count twice)
  # uncomment lines 7 and 9 to count only main snaks
  SELECT ?property ?propertyLabel ?count WHERE {
    {
      SELECT ?property (COUNT(?statement) AS ?count) WHERE {
        ?property a wikibase:Property;
                  # wikibase:claim ?p;
                  wikibase:novalue ?wdno.
        # ?entity ?p ?statement.
        ?statement a ?wdno. # note: if lines 7 and 9 are commented, ?statement may also be an entity with a truthy “no value” statement
      }
      GROUP BY ?property
    }
    SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
  }
  ORDER BY DESC(?count)