currency impact

Quick check on AUD/USD impact of recent AUD uplift: assuming around $280m a year in COGS, discounted from expected statutory disclosed amounts (say by 10-15%) for locally sourced inputs, distribution costs etc, derives a 1 cent impact (1/71), or say 1.4%, at 74 cents conversion being 4% or $11m in pre tax income on an annualised basis. Wondering if this is reasonable ballpark figure, noting effect flows through over time as existing hedges roll off post 31 December 2016. Some uplift also expected from 1 January 2016 adjustments to reduction in duty imposts.