Operating ExpensesExcluding other net charges and gains, operating expenses increased by 8% to $109.8 million for the second quarter of 2012, from $101.2 million for the second quarter of 2011. This reflects a $5.1 million (6%) increase in cash expenses and a $3.5 million (32%) increase in non-cash expenses, principally increased stock compensation expense.
|Three Months Ended June 30||Six Months Ended June 30|
|2011 US$m||2012 US$m||2011 US$m||2012 US$m|
|2.7||2.1||Depreciation and amortization||5.1||4.2|