Help with composing async Task .....

I must select distinct values from one column named YEAR from the database table.  I MUST use async Task<IEnumerable<variables>> for this code in my class library.

I need help with the body of the code in the class library. The goal is to return a list ofDistinct Years from the database table.

Code - need linq code.

public async Task<IEnumerable<mClerkTbl>> GetFiscalYearList()

{

      return await_mClerkTblRepository.......<-- HELP!!!

}