Several CEOs of the Financial Times Stock Exchange (FTSE) 100 companies earned massive seven-figure salaries last year (2016), according to the High Pay Centre’s August 2017 report on British CEO pay.

While these business leaders drew in healthy salaries, their incomes did slide 17% from 2015. The average FTSE 100 CEO earned $4.53 million British pounds, according to the study, which was a joint effort with the Chartered Institute of Personnel and Development (CIPD). The study took into account salaries on earnings reports, bonuses, employer pension contributions and incentives.

Here are the top five highest-paid CEOs of British firms that trade on the London Stock Exchange and are included in the FTSE 100:

1. Sir Martin Sorrell

Company: WPP Plc.

Salary: 48.1 million pounds ($64.4 million)

WPP Plc. (Wire and Plastic Products) is a multinational public relations company based in London. Its numerous advertising companies include IMRB, Olgilvy & Mather, Millward Brown, Grey and Burson-Marsteller. 

Sir Martin Stuart Sorrell is a British businessman. After privately investing in Wire and Plastic Products, he became CEO in 1985. He is the longest-serving CEO among FTSE 100 companies. Sorrell was knighted in 2000.

Sorrell’s salary is nearly twice the second-highest paid CEO of the FTSE 100.

2. Arnold W. Donald

Company: Carnival

Salary: 22.4 million pounds

Carnival UK’s P&O Cruises and Cunard Line are headquartered in Southampton, UK. The overall Carnival company posted 16.4 billion pounds in revenue and 2.3 billion pounds in profit in 2016.

Arnold Donald is an American. He began his career at Monsanto, holding numerous positions there, including senior vice president. Donald has been at the helm of Carnival since 2013.

3. Rakesh Kapoor

Company: Reckitt Benckiser Group

Salary: 14.6 million pounds

Reckitt Benckiser Group, headquartered in Slough, England, is a consumer goods company with brands that include Dettol, Strepsils and Airborne. It has operations in about 60 countries. Revenue was $9.9 billion British pounds in 2016.

Rakesh Kapoor, an Indian businessman, joined the company in 1987. He is known for his effective cost-cutting strategies and running the company like a small business. He also keeps a low profile, reportedly taking business class on flights that are less than six hours.

4. Pascal Soirot

Company: AstraZeneca

Salary: 13.4 million pounds

AstraZeneca is a pharmaceutical company based in Cambridge after having moved from Sweden in 2013. It is among the world's largest pharmaceutical companies, posting 23 billion pounds in revenue in 2016.

Pascal Soirot, a Swede, was recently rumored to be moving to Teva Pharmacetical Industries. But those reports have been refuted. He remains at the helm of AstraZeneca, a position he’s held since 2012.

5. Erik Engstrom

Company: RELX Group

Salary: 10.6 million pounds

The RELX Group is an analytics group based in London that operates in 40 countries. Its annual revenue is about $6.9 billion British pounds. Its market segments include scientific, technical and medical, legal, exhibitions, and technical/medical.

CEO Erik Engstrom, a Swede, has been leading the company since 2009. He was previously CEO of Elsevier and a partner at General Atlantic.