query: #inception decade barchart of library buildings in New South Wales
  #defaultView:BarChart
  SELECT ?year (COUNT(?year) AS ?count)
  WHERE {
    ?item wdt:P31 wd:Q856584; 
          wdt:P131 [ wdt:P131 wd:Q3224 ];
          wdt:P571 ?inception.
    BIND(STR(FLOOR(YEAR(?inception)/10)*10) AS ?year)
    SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en".}
  } GROUP BY ?year ?count ORDER by ?year