query: #defaultView:BarChart
  SELECT (str(?year) AS ?year)  (COUNT(?item) AS ?count)
  WHERE
  {
      ?item wdt:P31 wd:Q7889.
      ?item wdt:P400 wd:Q23882.
      ?item wdt:P577 ?_publication_date. 
      BIND ( year(?_publication_date) as ?year )
  }
  GROUP BY ?year
  ORDER BY ?year