The US government shutdown has blown a nearly $5 billion hole in federal workers’ finances. That’s the amount of back pay that has accumulated since the shutdown began on Dec. 22, according to calculations by data technology company Enigma.

Several key federal agencies have been without funding after negotiations on a new spending bill fell through because of disagreements over the border wall Donald Trump wants to build between the US and Mexico. The president is demanding more than $5 billion to get started on the project; Democrats are refusing to grant it. So far, neither party shows any sign of giving in.

At 24 days as of Monday (Jan. 14), the current government shutdown is the longest ever. Over that period, 826,531 federal workers have gone without their paychecks, according to Enigma. About half a million of them, those whose jobs are considered “essential,” are working without pay. The rest have been furloughed.

Having workers stay home is not only pinching their personal budgets; it’s delaying vital government activities, from trash collection to scientific research.

Here are current staffing levels at the federal agencies, as calculated by Enigma:

Some departments, such as Defense and Veterans Affairs, are fully staffed during the shutdown, because they already received funding from a previous spending bill.

But other agencies are having to make do with a significantly reduced staff. The Securities and Exchange Commission, for example, is currently operating with just 285 of its nearly 5,000 regular employees. There are a mere 20 out of 570 working at the Consumer Safety Product Commission, which oversees product recalls.

The National Endowment for the Arts, meanwhile, has a single employee, of a total 213, on the job. That’s one more than at the Advisory Council on Historic Preservation, whose workforce has been 100% furloughed during the shutdown.

Enigma compiled the data on affected workers from the contingency plans submitted by federal agencies to the Office of Management and Budget. The information on salaries comes from FederalPay.org, a non-governmental service that publishes pay scales for federal workers based on government data.

It also tracked the 2013 government shutdown, which was triggered when Tea Party Republicans refused to pass a spending bill that funded the Affordable Care Act. During that 16-day period, 883,392 federal workers were furloughed, over $3 billion in salaries were delayed, and $211 million worth of WIC food vouchers (for women, infants, and children) went unpaid.

Enigma is updating its delayed wage count for the current shutdown in realtime; it is rising at approximately $2,000 per second.

Congress has approved a bill that will pay back wages to furloughed workers—once the shutdown is over.

This post has been updated with revised federal salary data from Enigma.