How many percent of the mountains on Andes which are non-volcanic?
Percent of non-volcanic mountains = count(mountains = 'Andes' & type ! = 'volcano') / count(mountains = 'Andes') * 100%
SELECT CAST(SUM(CASE WHEN type != 'volcano' THEN 1 ELSE 0 END) AS REAL) * 100 / COUNT(*) FROM mountain WHERE Mountains = 'Andes'