CREATE TABLE PersonFriend (name VARCHAR, friend VARCHAR, year INT)
CREATE TABLE Person (name VARCHAR, age INT, city TEXT, gender TEXT, job TEXT)

Give me a histogram for how old is each gender, on average?, list in ascending by the mean age.
SELECT gender, AVG(age) FROM Person GROUP BY gender ORDER BY AVG(age)
SELECT "gender", AVG("age") FROM "Person" GROUP BY "gender" ORDER BY AVG("age") NULLS FIRST