109 AGL Energy Limited Annual Report 2011 2011 2010 2009 2008 2007 $m $m $m $m $m Present value of defined benefit obligations  (198.2) (209.1) (188.8) (154.7) (62.9) Fair value of plan assets  157.6 155.7 135.5 158.5 83.0 (Defi cit)/surplus  (40.6) (53.4) (53.3) 3.8 20.1 Experience adjustments on plan assets  1.7 5.1 (32.8) (15.2) 6.0 Experience adjustments on plan liabilities  (1.3) (1.8) (7.0) (4.2) 5.0 History of experience adjustments The consolidated entity expects to contribute $10.6 million (2010: $11.0 million) to the defined benefit plans during the next fi n a n c i a l  y e a r . The fair value of plan assets does not include any amounts relating to any property occupied by, or other assets used by, the consolidated  entity. Less than 0.5% of the fair value of the plan assets in the SuperSolution Master Trust – AGL Division comprises ordinary shares in the  Parent Entity. The expected return on plan assets is determined by weighting the expected long-term return for each asset class by the target allocation  of assets to each class and allowing for correlations of the investment returns between asset classes. The returns used for each asset class  are net of investment tax and investment fees. An allowance for administration expenses has been deducted from the expected return. The major categories of plan assets as a percentage of the fair value of total plan assets at the reporting date are as follows: The principal actuarial assumptions at the reporting date (expressed as weighted averages) were as follows: The consolidated entity makes contributions to a number of defined contribution superannuation plans. The amount recognised as an  expense for the financial year ended 30 June 2011 was $14.4 million (2010: $12.3 million). Defined contribution superannuation plans Principal actuarial assumptions Categories of plan assets SSMT  EF  EISS 2011 2010 2011 2010 2011 2010 % % % % % % Australian equities  30.7 31.0 35.0 37.0 30.0 29.0 International equities  28.6 26.0 27.0 25.0 18.0 19.0 Fixed interest securities  25.8 28.5 12.0 13.0 15.0 15.0 Property  5.0 5.4 10.0 10.0 12.0 12.0 Cash  4.7 6.9 6.0 6.0 7.0 7.0 Other  5.2 2.2 10.0 9.0 18.0 18.0 SSMT  EF  EISS 2011 2010 2011 2010 2011 2010 % % % % % % Discount rate (after tax) active members  4.8 4.7 4.7 4.5 4.8 4.7 Discount rate (after tax) pensioners  – – – – 5.2 5.1 Expected return on plan assets – active members  7.0 7.0 7.0 7.0 6.7 6.6 Expected return on plan assets – pensioners  – – – – 7.7 7.6 Expected salary increase rate  4.0 4.0 4.0 4.0 4.0 4.0 Expected pension increase rate  – – – – 3.0 3.0