Over 10pc of female staff earned bonuses past year compared to just 8pc of men, but men outnumber women throughout the company, from the boardroom down, making up 65.6pc of the workforce. By contrast, technology and education have the lowest pay gaps at 0.8% and 0.6%, respectively.
Introduced in the 1970s, the Equal Pay Act made it illegal to give men and women different pay or conditions for identical work.
However, Rowlands reported that women's median hourly rate - which takes the mid-point when all hourly rates are lined up from biggest to smallest, reducing the impact of one-off outliers - was 3% higher than men's and the median bonus gap was 47% in favour of women. Two-thirds of women aged between 18 and 34 rate career "high" on their list of life priorities, compared with 59 per cent of men.
By contrast women employees of EI's fully managed Bermondsey pub chain are paid seven per cent less than men. It showed that, of the highest-paid employees in 2016-2017, just under a third were women.
But Shropshire Council's figure was nearly three times that, at 20.8 per cent. The BBC's director general, Tony Hall, says the BBC's overall pay gap was 10 percent. Employers must also calculate the median gap, which looks at the difference between the midpoint of men and women's salaries. Instead, the government intend to publish industry-specific league tables, highlighting the employers failing to even out differences in salary between men and women.
In 2017 it became government policy that all United Kingdom companies employing 250 people or more must submit the details of their gender pay gap by April 4, 2018.
At the other end of the scale, construction firm Lindab Limited, based at Carousel Way, pay women 25.1 per cent more than men.
It is sometimes claimed that the gender pay gap should not be seen as a concern.
It is important to recognise exactly what the gender pay gap means.
Ryanair has one of the ten biggest gender pay gaps in Britain, with its submission showing very few women work in high-earning positions.
Kane's data, which he has outlined in a blog post for Civil Society Media, showed that charities compare favourably to pay gap data in private companies, at 15 per cent, and the public sector at 13 per cent.
What did the gender pay gap data show?
Rebecca Hilsenrath is chief executive of the Equality and Human Rights Commission (EHRC), which has the power to fine large companies that have not reported their gender pay gap details. Although men and women are by law required to be paid the same for the same job, there are differences in the hierarchy of the workplace, where men often dominate management.
"Everyone in the CAA contributes to regulation and protecting the public, however we have many more men than women in senior roles and by contrast many more women than men in junior roles", it said.