Aircraft pilots and engineers are UK's highest paid workers with average salaries of

[wiggy]

Along with the meaning of terms such as "mean", "median" and "mode", it's also worth bearing in mind the following from the Guardian piece:

The data is taken from their PAYE record – it includes bonuses, but the figures do not cover the self-employed or celebrities who don’t appear on company payrolls.

(my emphasis)

Edit to add: FWIW having had a harder look it seems the ONS has gone for the median figures.... that said it's still meaningless (IMHO) since as VoP points out below it excludes the self employed/service providers.