Oo ken you bad man!
The best businessmen (that includes you) know thier figures, you yourself endorse the charging of better prices to make an honest living in our industry so you must know your figures somewhere.
As for a national average how would you work it out? there are so many different ways, ie if you have multiple items at a job 3pc, lounge, diner, hsl, 3 bedrooms you may want to discount your price as the work won't take as long in 1 trip (breaking it up) as 7 trips with travel and expenses.
I got a pack from DP print and some cleaners on their leaflets had prices of from £15 a carpet, I start from £59 there is too much difference to work an honest average out.
Shaun
PS don't start on suite prices!