query: embed.html##defaultView:BubbleChart
  SELECT ?country ?countryLabel (COUNT(?item) AS ?count) WHERE {
    ?item wdt:P31 wd:Q3305213 .
    ?item wdt:P195 ?collection .
    ?collection wdt:P17 ?country . 
  	OPTIONAL {
  		?country rdfs:label ?countryLabel 
  		filter (lang(?countryLabel) = "en")
  	}
    } GROUP BY ?country ?countryLabel
  ORDER BY DESC(?count)