No worries,
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))
Your formula works out the average of the 10 most recent numbers, excluding non numeric values.
=AVERAGE(K1:T1)