Conflicting figures provided political ammunition for both sides during the Brexit debate...
Since Theresa May stated that Article 50 will be triggered before the end of March of next year, attention has turned to the exact terms of the UK's uneasy break-up with the EU.
This process could be particularly messy for Northern Ireland.
How important is the EU to its economy?
In 2015 the UK's gross contribution to the EU was £12.9bn. There is not a specific regional breakdown detailing where this money comes from, but as it represents close to 3% of Britain's total population it is estimated (by some) that NI sent £374m to Brussels.
In return it received £320m from the EU's common agricultural fund, fisheries fund, and the jobs, growth and investment initiative.
A special peace and cross-border fund also added some £50m. Science, education and research funds were worth an extra £10m.
This adds up to a total return of £380m on the £374m contribution.
Lies and stats...
However, these figures served as a source of contention as both sides of the referendum campaign claimed that the other had cooked the books to make the contribution seem greater or smaller than it actually was.
This swung from Leave Voters saying EU membership cost the region £67m - to a BBC fact check finding that the North's contribution had been overstated, and that it actually gains £58m a year through membership.
The main source of this discrepancy is due to a rebate on the UK's contribution not being accounted for in 2015.
Population percentage is also a crude means of calculating the Northern Irish contribution. Tax generated by NI is closer to 2.5% of the UK's total (down from the 3% population stake) this greatly increases the surplus that EU membership generates if you use it to calculate the NI contribution.
A report from the Nevin Economic Research Institute highlighted Northern Ireland as the region which will be "most affected" by the UK's exit.
It says that Brexit poses a "disproportionate risk for Northern Ireland in the short to medium term."
"Much of the debate on Brexit at the national level in the UK has focused on how much the country would lose or gain financially from either decision. Once again it is not possible to be definitive on this matter," the report states.
The Nevin Institute's figures forecast that the best case scenario would be a 'soft break' with the EU - "Depending on exactly how Northern Ireland’s contribution is calculated it would fair to suggest that the best Northern Ireland could hope for would be to break even in the event of a Brexit," it concludes.
It is impossible to quantify the full effect Brexit will have on the UK's finances - but the Northern Irish agri-food sector looks vulnerable, and the tone of negotiations suggest Britain is heading for a 'hard' exit.
If the UK puts migration control ahead of economics and ultimately faces an economic shut-out from the Union this industry could see significant increases in the cost of doing business.
The Nevin Institute highlights agriculture and manufacturing as the two industries most exposed to the Brexit-fallout.
Bombardier, Northern Ireland's largest manufacturing employer, called on its staff to back the 'remain' side in the debate. "It is better for our company that the UK remains within the EU," it told workers.
NI's farmer association and main trade unions remained neutral during the debate.
Northern Ireland is on the way to dropping corporation tax from 20% to the Republic's 12.5% rate to compete for FDI - but these efforts could suffer if the UK is locked out of the Single Market.
In an interview yesterday, Minister for Foreign Affairs Charlie Flanagan warned that the reintroduction of a hard border on the island of Ireland cannot be ruled out.
Mr Flanagan told Newstalk Breakfast that the possible re-imposition of a border between Northern Ireland and the Republic was a "matter of grave concern" to the government.
He said he had impressed upon his EU colleagues the "unique situation" in Ireland and "the fact that we cannot go back to the old days of a heavily fortified border."
Taoiseach Enda Kenny is to bring a memo to cabinet this morning on Brexit.