If you wish it to be alphabetical, go to the box labeled "Select sort method:" and use the drop down to select "Last Name". Then click on the "Sort" button on the far right. That will give you an alphabetical listing by last name.
By selecting "Years on Board", you'll get a list which sorts by the first year someone was on board (provided we have that information).
You can also sort ascending or descending on any sort field but missing information (blanks) are assumed to come before anything else.