Average annual growth rate excluding non numeric values.

[p45cal]

I'm looking for the Average annual growth rate of the 10 most recent numbers, excluding non numeric values. This formula works out the difference between the side by side years and then averages it.

=AVERAGE((L1/K1-1),(M1/L1-1),(N1/M1-1),(O1/N1-1),(P1/O1-1),(Q1/P1-1),(R1/Q1-1),(S1/R1-1),(T1/S1-1))

I think this will give you misleading results:
You want the annual growth and you say the years are side-by-side. So if there is a missing value (a missing year) then the two values either side of that missing value represent 2 years' growth. If there are 3 missing values, then the two values either side of that represent 4 years' growth, so you can't use the likes of (N5/P5-1) to represent one year's growth, because it occurred over 2 or more years.
Wouldn't you get more meaningful results if you took the value 10 years ago, and the value now, work out the growth over that 10 year period (don't subtract 1) and raise it to the power 1/10? That should give you the annual (compounded) effective rate of growth. If you haven't got exactly 10 years, then choose the latest value and one that is as close as you can to 10 years ago and raise to the power 1/n, n being the number of years between those two values.
On top of that, if you don't have the most recent values (rows 4,5,7 & 15) then you should state which is the last year with figures at the same time as stating the average growth rate.

For row 1 that would be:

=(T1/K1)^(1/9)-1

As an aside, with a contiguous 10 values as you have in row 1, your formula can be simplified to:

=AVERAGE(L1:T1/K1:S1-1)

or array-entered:

=AVERAGE(L1:T1/K1:S1)-1

…now if xld can work his magic and tweak his formula?