ALI T wrote:
operational materials cant have been to important as they drop off to almost nothing from 2009:
Indeed, but if you look at equipment costs they've gone through the roof, so it's possible that the same costs previously allocated to operational materials have in later years been allocated to equipment costs, but when it comes to the bottom line it doesn't make a whole lot of difference.
Look at gas and electricity, for example. It's fairly steady for the first two year, then reduces to nil

then for the next two years it's nearly double what it was originally
What may have happened is that someone forgot to allocate the cost in middle two years, so they're increased the figures in the last two years to compensate. If you look at the last two figures they're identical, suggesting that they don't actually represent the true costs for the year but a figure someone came up with as a readjustment spread over two years.
The problem with these things is that you'll have people sitting in the accounts department somewhere who don't really know what's going on.
Thus you might get different staff in different years who allocate the same expenditure to different accounts, so the numbers look iffy but in reality it's not of huge significance.
Likewise, as regards the electricity bill that's likely to cover several different departments and has to be allocated out. So if someone cocks up or a new member of staff doesn't know properly what's going on then this may all be forgotten about, so you get a zero figure for a couple of years. But later someone notices this, so you might see an adjustment in later years as above.
And the problem with auditing and the like is that they can't go through absolutely everything, so they just pick things at random, and the smaller numbers in particular may never be checked at all.
Not that I'm saying everything is hunky dory, and most of the above is just speculation, but on the other hand it would be wrong just to jump to conclusions just because some of the figures seem inconsistent - there's probably a rational explanation for most of it.