NOTES TO THE FINANCIAL STATEMENTS CONTINUED FOR THE FINANCIAL YEAR ENDED 30 JUNE 2011 The following summarises the significant methods and assumptions used in estimating fair values of financial assets and financial  liabilities for disclosure purposes: Note 3. Financial Risk Management  (continued) (d) Fair Value Estimation  (continued) The carrying amount is fair value due to the liquid nature of these assets. The carrying amounts of receivables are assumed to approximate their fair values due to their short term nature. The carrying amounts of security deposits are assumed to represent their fair values based on their likely realisability profile. Due to the short term nature of these financial liabilities, their carrying amounts are assumed to represent their fair values. Cash and Cash Equivalents Security Deposits Receivables Trade and Other Payables Note 5. Expenses Loss before income tax includes the following specific expenses: 54 Karoon Gas Australia Ltd  Annual Report 2011 Consolidated 2011 2010 Note  $ $ Note 4. Revenue Interest income from unrelated entities  14,225,048 6,459,623 Total revenue  14,225,048 6,459,623 Sundry income  - 914 Total other income  - 914 Depreciation and amortisation expense:  - depreciation of plant and equipment  15  335,347 246,223 - amortisation of computer software  16  195,898 169,444 Total depreciation and amortisation expense  531,245 415,667 Exploration and evaluation expenditure expensed or written off:  - exploration and evaluation expenditure expensed  780,662 136,812 - exploration and evaluation expenditure written off  17  3,881,892 - Total exploration and evaluation expenditure expensed or written off  4,662,554 136,812 Finance costs:  - bank charges  447,592 244,275 - interest expense to unrelated entities  8,698 - Total finance costs  456,290 244,275 Share-based payments expense  27(d)  5,069,475 5,289,047 Rental expense on operating leases – minimum lease payments  668,041 228,395 Net loss on disposal of plant and equipment  82,945 -