How many {retirement age} are for {Australia} ?
How old do you have to be to retire in Australia?
What's the retirement age in Australia?
SELECT ( COUNT ( ?b ) AS ?t ) { resource:Australia property:retirement_age ?b }
SELECT (COUNT(?obj) AS ?objs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q408> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P3001> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
} 

SELECT (COUNT(?obj) AS ?value ) { wd:Q408 wdt:P3001 ?obj }
1