query: embed.html#SELECT ?decade (COUNT(?decade) AS ?count) WHERE {
    ?item wdt:P31 wd:Q5 .
    ?item wdt:P569 ?birth .
    ?item wdt:P106 wd:Q1028181 .
    ?item wdt:P21 wd:Q6581072 .
    BIND( year(?birth) as ?year ). 
    BIND( ROUND(?year/10)*10 as ?decade ) .
    FILTER( ?year > 1850)
    FILTER( ?year < 2010)
    } GROUP BY ?decade
  ORDER BY ?decade