The annual Government Expenditure and Revenue Scotland (GERS) figures inspire almost as much passion, for and against, as their footballing namesakes.

Independence supporters complain they provide a partial, if not misleading, picture of the public finances, and bear little resemblance to a Scotland in full control of its economic fate.

Fans on the Union, while conceding GERS is not whole story, say the statistics are nevertheless the best guide we have to the starting point for an independent Scotland.

Although GERS is guaranteed to produce bickering at any time, the figures for 2016/17 are particularly contentious, as they cover what would have been Scotland’s first year as an independent country if there been a Yes vote in September 2014.

However you cut them, they do not make happy reading for the Nationalist team.

The 650-page White Paper on independence launched by Alex Salmond and Nicola Sturgeon contained a single table of economic projections.

They forecast North Sea oil revenue of between £6.9bn and £7.8bn, and a manageable deficit of between £2.7bn and £5.5bn (1.6 to 3.2 per cent of GDP), depending on how big a share of the UK’s national debt Scotland inherited.

The GERS figures for 2016/17 show events took a very different course.

The halving of the oil price means North Sea revenues were less than 3 per cent of that forecast last year, a “trivial” £208m, as the economist John McLaren called it yesterday.

It meant Scotland’s deficit was far higher than the First Minister and her predecessor hoped, at £13.3bn, or 8.3 per cent of GDP, against a UK deficit last year of 2.4 per cent of GDP.

This was £7.8bn worse than the worst case scenario the SNP government set out before the referendum, and £10.5bn worse than its most optimistic prediction.

If there had been a Yes vote, year one of independence would have seen spending cuts, tax rises and borrowing costs of a wholly different order to anything seen during devolution.

As Ms Sturgeon argues, the powers of independence would have allowed Scotland to plot a different economic course, but that does not change the grim picture for year one.

It is hard to set sail for the promised land with a £13bn deficit as an anchor.

To be fair, the White Paper’s figures were based on data for 2011/12, which now seems an awfully long time ago.

The oil price assumption of $113 a barrel was based, very reasonably, on the average of the preceding two years, and was not the highest forecast used by economists at the time.

Asked about the gulf between the White Paper and reality, Ms Sturgeon rejected the opposition charge that she had tried to “con” voters into backing a Yes vote on the back of bogus numbers, and said no one had foreseen the oil shock that followed their publication.

“The figures we put forward were reliable at the time,” she said. “Circumstances changed.”

Indeed they did. Profoundly so. But unlike the economist John Maynard Keynes, who famously said “When the facts change, I change my mind”, Ms Sturgeon shows no sign of changing her mind about the incontestable case for independence.

Although she has shelved her immediate plans for one, she says another referendum before 2021 remains “likely” because of Brexit, if she can extract the powers from Westminster.

But a side-by-side comparison of the White Paper and GERS shows she has now has an almighty credibility problem to overcome before she dares go to the voters.

If the last White Paper can turn out to be so wide of the mark, why should people have any confidence in the next one put before them?

It may be true that no one foresaw the last oil shock, but an oil shock of some kind, at some point, was always on the cards, but she has yet to explain how Scotland would cope.

Almost a year ago, Ms Sturgeon announced an SNP Growth Commission, chaired by her friend and former MSP Andrew Wilson, which was supposed to provide answers to thorny economic problems like the deficit, oil and the currency in an independent Scotland.

Its subterranean work remains ongoing, although Ms Sturgeon has promised to publish its findings in full when it does eventually surface. Its membership does not inspire confidence.

While there are some academics on board, it is stacked with SNP politicians and independence supporters unlikely to interrogate the facts with the rigour required.

Is Finance Secretary Derek Mackay, one of the Commission members, likely to pipe up and question whether independence is worth the price of admission?

The White Paper has proved not to be robust, and that was in large part the work of civil servants. The Growth Commission is surely even more prone to “optimism bias”.

GERS has exposed Ms Sturgeon’s credibility gap, as well as the economic one.

If she is to build a case for independence, then when the facts change so must she.

An SNP Growth Commission pushing a foregone conclusion won’t alter anything.