Show all locations and the number of gas stations in each location ordered by the count, please?
select location, count ( * ) from gas_station group by location order by count ( * )
What is the name of the location that has more than one gas station?
select location from gas_station group by location having count ( * ) > 1
What year was more than one gas station opened in?
select open_year from gas_station group by open_year having count ( * ) > 1