query: SELECT
    (wd:Q2481549 as ?item) 
    ("rect" as ?type)
    ("400" as ?width) 
    ("200" as ?height) 
    ("Number of zoos with polar bears" as ?legend) 
    ("country" as ?xAxisTitle) 
    ("zoos" as ?yAxisTitle)
    (GROUP_CONCAT(?country;separator=",") as ?x)
    (GROUP_CONCAT(?count;separator=",") as ?y)
  WHERE
  {
    { 
      SELECT ?country (COUNT(DISTINCT ?zoo) as ?count)
      {
        ?zoo wdt:P1990 wd:Q33609 . 
        ?zoo wdt:P31 wd:Q43501 .
        ?zoo wdt:P17 / wdt:P901 ?country .
        SERVICE wikibase:label { bd:serviceParam wikibase:language "en" }
      }
      GROUP BY ?country
      ORDER BY ASC(?count) ?country
    }
  }