Help with Game Setting

In the Station View, I clicked on the arrows next to the Market column and it arranges the airports I have from the smallest to the biggest (and vise versa). My question is, I am unable to get it back to the default where the airports are listed by alphabetical order. Can anyone tell me how to get it back to the original? Thanks.

You can sort the table as you like. Click on the header of any column to sort it as you wish.

To add to this answer: By default it is ordered by pax capacity, I think. (Passengers - Cap)