text: June 30, 
  
  Assumptions used to determine benefit obligations at year end: 
  
  Discount rate 
  
  Rate of compensation increase 
  
  Assumptions used to determine net periodic benefit cost: 
  
  Discount rate  **3.5 %** 4.3 % 
  
  Expected return on plan assets  **7.5 %** 7.5 % 
  
  Rate of compensation increase  **5.5 %** 5.5 % 
  
  Due to freezing participant benefits in the SERP plan, the rate of compensation increase is no longer applicable. The assumed health 
  care cost trend rates used in measuring the accumulated benefit obligation for retiree health care benefits were 7.5% and 8% as of 
  June 30, 2012 and 2011, respectively, decreasing to 5% by 2018. 
  
  A one-percentage point change in the assumed health care cost trend rates would have had the following effects as of June 30, 
  2012 and for the year then ended: 
  One-Percentage Point 
  
  Increase  Decrease 
  
  Effect on total service and interest cost components of periodic expense  $ 
  48 
  $  (39 ) 
  
  Effect on postretirement benefit obligation 
  854 
  (701 ) 