Popular consumer brands Discovery Communications, Chipotle Mexican Grill and CVS pay their chief executive officers more than a thousand times what they pay their typical worker, giving them the biggest internal pay gaps among S&P 500 companies, according to a study released on Tuesday.

The research from job-hunting website Glassdoor.com provides an early glimpse of data that publicly traded companies will be required by the Securities and Exchange Commission to report starting in 2017. On average, the research showed that a CEO of an S&P 500 company makes 204 times as much as the company’s median worker.

“I don’t think most people are aware of the inequality of payrolls within a firm,” said Glassdoor’s chief economist, Andrew Chamberlain.

The study used CEO compensation figures reported by 441 S&P 500 companies through Aug. 14 and Glassdoor.com user reports about salaries at those companies. Only companies for which Glassdoor had 30 or more worker salary reports were included. The data could be skewed if workers under-counted tips or bonuses, Glassdoor said.

Cable network operator Discovery had the biggest pay gap. Its CEO, David Zaslav, was the highest-paid among S&P 500 companies last year, at $156 million. That was 1,951 times the amount paid to Discovery’s median worker, Glassdoor found.

In second and third place were restaurant chain Chipotle and drugstore operator CVS, whose CEOs in 2014 received $28.9 million and $32.4 million, respectively, both more than 1,000 times their median workers, according to the study.

CVS spokeswoman Carolyn Castel said its employees have opportunities to be promoted and receive higher pay, while its CEO is paid in line with industry standards. Discovery and Chipotle representatives did not return messages requesting comment.

The Glassdoor study found the average CEO received $13.8 million, while the median worker at those CEO’s companies made an average of $77,800.

Glassdoor’s findings were in line with other studies, said Todd Sirras, managing director of compensation consulting firm Semler Brossy. He said the new reporting requirements could add pressure on companies to change their executive pay plans.

“It will be one more arrow to sling at companies,” he said.

In a few cases, workers made more than their CEOs, such as at Google Inc., where CEO Larry Page got $1 in 2014. His median worker got $153,150, Glassdoor said.