How many {ethnic group} are to/by {Berbers} ?
How many Berber ethnic groups are there?
SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P172 wd:Q45315 }
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/P172> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q45315 .
} 

There are how many Berber ethnic groups?