query: SELECT (SAMPLE(?p) as ?item) ?scale (COUNT(DISTINCT ?p) as ?count) (MIN(?area) as ?min)  (MAX(?area) as ?max) 
  {
      ?p wdt:P882 [] ; wdt:P17 wd:Q30 .
      ?p p:P2046/psn:P2046/wikibase:quantityAmount ?a .
      BIND(ROUND(?a/2589988) as ?area) 
      BIND(strlen(str(?area)) as ?scale) 
  }
  GROUP BY ?scale 
  ORDER BY ?scale