SELECT p.cf,count(*)
FROM sparqltable (select ?cf  ?cat ?num
	WHERE{
		?x rdf:type 'Persona'.
		?x :codFis?cf.
		?x :effettua?s.
		?s rdf:type 'Singola'.
		?s :PSP?t.
		?t rdf:type 'PostoAssegnato'.
		?t :PP?u.
		?u rdf:type 'Posto'.
		?u :num?num.
		?u :categoria?cat.
		})p
WHERE p.cat = '1'
GROUP BY p.cf