query: #defaultView:BarChart
  SELECT (str(?year) AS ?year)  (COUNT(?person) AS ?count)
  WHERE
  {
  	?person wdt:P3421 [] ; wdt:P569 ?DOB .
    BIND ( year(?DOB) as ?year )
    FILTER( ?year > 1000)
  }
  GROUP BY ?year
  ORDER BY ?year