12th January 1981   26th January 1981   9th February 1981  
             
       
  23rd February 1981   6th March 1981   16th March 1981  
             
       
  6th April 1981   20th April 1981   4th May 1981  
             
       
  18th May 1981   1st June 1981   15th June 1981  
             
       
  29th June 1981   13th July 1981   27th July 1981  
             
       
  10th August 1981   31st August 1981   21st September 1981  
             
       
  5th October 1981   16th November 1981   30th November 1981  
             
         
  14th December 1981   28th December 1981