query: #by Jura1, 2016-05-04
  SELECT ?count ?datetime_precision_label ?datetime_precision
  {
    {
      SELECT ?datetime_precision (count(DISTINCT(?node)) as ?count)
      {
          ?node psv:P2754/wikibase:timePrecision ?datetime_precision
      }
      GROUP BY ?datetime_precision
    }
    ?item wdt:P2803 ?value
    FILTER (?datetime_precision = ?value)
    SERVICE wikibase:label { bd:serviceParam wikibase:language "en,en" . ?item rdfs:label ?datetime_precision_label  }
  }
  ORDER BY DESC(?count)
  LIMIT 10