The fast food turnover crisis is growing worse as some chains lose 100% of their workers every year.

If this sounds like mathematical trickery on the part of statisticians, it isn’t. 100% of workers at Panera Bread are lost each year as employees who leave are replaced by other employees who also leave very quickly.

The phenomenon of abnormal turnaround times for fast food employees is only growing worse, according to various industry metrics. The troubles at Panera Bread are a symptom of a common and quickly-worsening labor problem in the US fast food industry. Panera Bread is actually now a particularly bad example of restaurant worker turnover rates, as 100% is currently good in the fast food industry. Take it from Panera Bread CEO Michael Bufano, who explains “In the restaurant industry, turnover is 130%, turning over more than a full workforce every year.”

The Bureau of Labor Statistics puts the turnover rate for the restaurant sector at 81.9%, but industry estimates go much higher, topping off at 150%. The problem is that turnaround is so weak in the sector it’s becoming hard to keep track of. While there are these conflicting statistics on the matter, the thing everyone can agree on is that the situation has grown worse in recent years.

The reasons for this worrying trend can be traced to the fast food industry’s attempts to standardize the routine of workers, taking much of the skill aspect out of the picture. The idea was to create turnover-proofed jobs, which worked very well for fast food companies for decades. If a worker is lost, they’re easily replaced and the cost to the company is minimal. Right now, this labor and HR model is being challenged across the economy. Now, demographic and labor trends are pushing this outdated model to its limit. As the fast food companies start to put a dollar value on the cost of this new trend, you can expect changes to start coming.