Those good folks at the Guardian have published the WP performance data by provider.
A4e have 5 areas. Their best performance was in South Yorkshire, with 3.55%. Their worst was in the Thames Valley, with 2.78%. The average for all 5 areas is 3.28%. A4e isn't the worst but it's far from the best.
Krishnan Guru-Murty has tweeted: "A4e founder Emma Harrison not available to explain why her claim #c4news figures were wrong turned out to be, er, wrong."