what is the {point in time} for {Benin} has {Human Development Index} as {0.477} ?
when did the human development index increased to 0.477 in Benin?
SELECT ?value WHERE { wd:Q962 p:P1081 ?s . ?s ps:P1081 ?x filter(contains(?x,'0.477')) . ?s pq:P585 ?value}
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q962> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1081> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <0.477> .
?statement <http://www.wikidata.org/entity/P585> ?value. 
} 

On what date did the Human Development Index in Benin increase to 0.477?