PREFIX schema: PREFIX property: PREFIX xsd: SELECT ?yn (max(?o3) as ?maxo3) WHERE { ?s property:type ?b . ?s property:ozoneClassification ?class . ?obs schema:station ?s . ?obs schema:O3 ?o3 . ?obs schema:year ?year . ?year property:yearNum ?yn . ?obs schema:sensor ?sensor . ?sensor property:statisticShortName "Max"^^xsd:string . FILTER(?b = "Background"^^xsd:string && ?class in ("suburban"^^xsd:string, "urban"^^xsd:string) && ?yn >= 2000 && ?yn <= 2014) } GROUP BY ?yn