How many {deepest point} are to/by {Persian Gulf} ?
How many of the deepest points are in the Persian Gulf?
SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P1589 wd:Q34675 }
SELECT (COUNT(?sub) AS ?subs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?sub .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1589> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q34675 .
} 

In the Persian Gulf, how many deepest points are there?