dForceGraph: The population of South America per country

The graph (well, it's a tree.) draws the structure Asia -> part of continent -> country. The colors represents the different continents, the size the population of the country. The animation is very snappy in Chrome, and not so snappy in other browsers.

The element which draws the above chart:

<div id="sgvzl_example_query" 
   data-sgvizler-endpoint="http://sws.ifi.uio.no/sparql/world" 
   data-sgvizler-query="SELECT ?node ?parent ?size ?color WHERE{ { [rdfs:label ?node ] w:isCountryInRegion [rdfs:label ?parent] ; w:isCountryInRegion ?color ; w:isCountryInContinent [rdfs:label &quot;Asia&quot;] ; w:hasCountryPopulation ?size } UNION { [rdfs:label ?node] w:isRegionInContinent [rdfs:label &quot;Asia&quot;,?parent] ; w:isRegionInContinent ?color } } ORDER BY ?size" 
   data-sgvizler-chart="dForceGraph" 
   data-sgvizler-loglevel="2" 
   style="width:800px; height:400px;"/>

The results of the query in gTable