query: #defaultView:BarChart
  SELECT (str(?year) AS ?year)  (COUNT(?person) AS ?count)
  WHERE
  {
  	?person wdt:P1344 wd:Q9680 ; wdt:P1532 wd:Q142 ; wdt:P569 ?DOB .
    BIND ( year(?DOB) as ?year )
  }
  GROUP BY ?year
  ORDER BY ?year