query: #defaultView:BarChart
  SELECT(SAMPLE(?year) AS ?year) (COUNT(?item) AS ?citesFounded)
  WHERE
  {
    ?item wdt:P31 wd:Q515 . # instance of city
    ?item wdt:P17 wd:Q30 . # in U.S.
    ?item wdt:P571 ?inception . # inception
    SERVICE wikibase:label { bd:serviceParam wikibase:language "en" }
    BIND(str(YEAR(?inception)) AS ?year)
  } GROUP BY ?year