It's a stalled picture which means we are seeing no progress.
The date has remained the same for the last three years, which the Fawcett Society says shows the lack of progress on tackling the gap, and that it will take another 100 years to gain equal pay at the current rate.
So what is going on? "I hope that in a few short years we'll be saying 'how is it possible that women could be paid less for the same work as men?' Are we willing for our daughters to be paid less than our sons?"
As for the government, Ms Walker says it needs to start joining the dots between the gender pay gap and sexual harassment.
It is not clear from the data why this is happening but it suggests a gap in starting salaries which inevitably puts women on the wrong track for their working lives.
Their figures also report that the pay gap is much wider for certain groups - including BAME women, skilled trade workers and high-earners.
The uncomfortable reality for us all is that a culture that tolerates or even fosters sexual harassment probably won't be paying women fairly either. Brazilian footballer Neymar's salary is just as uncharacteristic of a normal man's pay pack as it is of a woman's.
Nicky Morgan, Conservative MP said "We've seen the best employers make ground breaking strides in tackling gender inequality". London still has the biggest gap at 20.7% but it has at least reduced by 3 percentage points. It is lowest in Wales, at 8.3%, and the North East, at 10.2%.
'The work women do, the industries they work in, and the caring responsibilities they generally shoulder are not valued by our society - not enough to pay them a fair wage.
So what do we do about it?
It is still taboo to talk to your colleagues about what they earn. Equal Pay and the gender pay gap aren't actually the same thing, but they are two signs of the same coin (sorry). That is why we have introduced a legal requirement for all large employers to publish their gender pay and bonus data by April 2018. We need enforcement action against any who don't comply. There are no excuses, employers now need to get on with the job of publishing their pay gap and pledge to improve workplace equality'. We also believe pay gap reporting should cover race and disability too. We pay all Scottish Government staff, including NHS workers and adult social care staff, the Real Living Wage. But with concerted action we can do it. Make your #paygappledge and tell us what you will do.
"We are going backwards and that is extremely worrying", Sam Smethers, Fawcett Society chief executive, said in a statement. Today they are encouraging people across the United Kingdom to pledge to do their bit to tackle unequal pay - whether that's workers starting a conversation with colleagues or companies and Government making tangible changes.