Ann: Quarterly Cashflow Report , page-10

I was actually wanting to ask someone on here about the hedge, as I'm not that familiar with hedges.
From the quarterly I deduced the following, possibly incorrectly?:
Hedge facility of up to 50% of shipments over 18 months(900,000 tonnes) But I can only see a total of 330,000 tonnes over 18 months that were committed to. And the actual benefit from this will depend on the premiums paid for this hedge?

Please note the question marks as I'm not sure if I have interpreted this correctly. Feedback greatly appreciated.