Asked about this at PMQs.
She goes on about a specific group of police who started in 2010 and were able to take advantage of the automatic increments etc that happened in that time plus the increase in the personal allowance.
Clearly explained in More or Less - 8 minutes in
www.bbc.co.uk/programmes/b093hf8v
The figure she quoted applied to 4% of police officers. It's the same thing she says about nurses, teachers etc.
Technically, she is correct to say that new starters in 2010 have seen their take home pay increase by 32%.
But the overwhelming majority haven't.
Sir Humphrey would be proud. I hope all those Tory MPs agreeing with her understand that she is being disingenus.