How many {people or cargo transported} are to/by {coal} ?
Which is the number of people or cargo transported to coal?
How many people or cargo transported to coal?
SELECT ( COUNT ( ?b ) AS ?k ) { ?b property:people_or_cargo_transported resource:coal }
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/P3437> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q24489 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P3437 wd:Q24489 }
3