Generate sqlite SQL query only and with no explanation. The query should end with a semicolon ';'.
[Tables and columns in the database]
student: major, city_code, stuid, lname, age | dorm: gender, dorm_name, dormid, student_capacity | lives_in: room_number, dormid, stuid | dorm_amenity: amenity_name, amenid
[User's question]
Find the number of students who is older than 20 in each dorm.
[Task description]
Please generate an executable sqlite SQL query to answer the above question. 
[SQL]
select count ( * ) , dorm.dorm_name from student join lives_in on student.stuid = lives_in.stuid join dorm on dorm.dormid = lives_in.dormid where student.age > 20 group by dorm.dorm_name ;

[Tables and columns in the database]
singer: country, age, name, singer_id, song_name | stadium: location, name, capacity, highest, lowest | concert: theme, year, concert_id, concert_name, stadium_id | singer_in_concert: concert_id, singer_id
[User's question]
What are all distinct countries where singers above age 20 are from , ordered by age from the oldest to the youngest .
[Task description]
Please generate an executable sqlite SQL query to answer the above question. 
[SQL]