How many {endemic to} are to/by {Arkansas} ?
What number of species are endemic to Arkansas?
How many species are endemic to Arkansas?
SELECT ( COUNT ( ?v ) AS ?p ) { ?v property:endemic_to resource:Arkansas }
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/P183> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q1612 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P183 wd:Q1612 }
10