human
366) Compute average year of buildings that do not have addresses or geometry.
gpt
```sparql
PREFIX :<http://example.org/ontology#>
SELECT (AVG(?y) AS ?avgYear)
WHERE {
  ?b a :Building ;
     :hasConstructionYear ?y .
  FILTER NOT EXISTS { ?b :hasAddress ?addr }
  FILTER NOT EXISTS { ?b :hasGeometry ?geom }
}
```