What is {position held} of {Charles G. Dawes} that is {start time} is {1929-4-16} ?
What position did Charles G. Dawes hold starting April 16, 1929?
SELECT ?obj WHERE { wd:Q184565 p:P39 ?s . ?s ps:P39 ?obj . ?s pq:P580 ?x filter(contains(YEAR(?x),'1929')) }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q184565> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P39> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
?statement <http://www.wikidata.org/entity/P580> <1929-4-16>
} 

What spot did Charles G. Dawes have authority over beginning April 16, 1929?