I know I'll get flamed for it and told that you can prove anything with statistics, but how can you make decisions without facts?
Cue Rain Man comments.
I'd only take issue with that fact that average means average. Median and all the rest of it is a complicated way of explaining a 'typical' wage 
This is where you're being misled and why people think that statistics can lie.
When someone says "average" most people automatically relate it to the "arithmetic mean" which is the sum of all the salaries divided by the number of people. This is indeed
an average, but it's not
the average.
Unfortunately, "median" (as above) and "mode" (most common salary) are all
legitimately referred to as "average". The word "average" refers to all three.
That's why you'll get a manager in a big firm saying the average salary in this firm is £25K(so your salaries are OK) and a union leader saying it's £30K (so our salaries need to go up) and they can both be telling the truth.
"Average" is not equivalent to "mean"!
Don't take my word for it:
From Wikipedia antry for average "Many different descriptive statistics can be chosen as a measure of the central tendency of the data items. These include the arithmetic mean, the median, and the mode."
From Wiktionary: "The term average may refer to the statistical mean, median or mode of a batch".
Seriously, it's one of the most misused words in politics. Always wonder what someone really means if they just use the catch-all word "average".
Vin