You can find the PDF here.
In explaining the abnormal charges from previous years there is the following explanation:
Our best estimate for misappropriated fuel of $18.0 million was recorded in 2012 within the aggregated income statement. This estimate has been based on extrapolation procedures and has therefore involved the use of estimates. We have taken a number of measures to mitigate the risk of further such losses occurring, such as employing a specialized in-house fuel consumption control team. The investigation is ongoing, however in 2013 there have been no developments which have led to an amendment to our original estimate.
Wholesale fuel prices are less than $1000 per tonne. Even by the time you get it to Sierra Leone the price is likely to be less than $1500 per tonne.
The amount of fuel stolen is likely to be over 10 thousand tonnes.
A quite large tanker truck contains 35 tonnes of fuel.
So this is 285 tanker trucks. Probably more as I have rounded down the amount of fuel and up the size of a tanker truck.
One per working day.
I wonder how they didn't notice them driving away.