The figures for UK airlines are collated and published by the CAA. Here is the link to the latest information.
http://www.caa.co.uk/docs/80/airline...rseas_2009.pdf
The average expenditure a head of £31,400 for cabin crew includes gross salary, overtime pay, sales commissions, flying pay, subsistence allowances and all crew hourly flight allowances. All payroll-based employer's costs such as NI and health insurance are excluded.