My EEE tells me which characters I use most

After a handful of months my EEE shows clearly which characters I use most.
That is to say: E, R, T, I, O, A, S, L, C, N, M and "SPACE".

How I figured out? The keyboard is worn. But not in an unpleasant sense!
It's just that the keys were slightly rugged and now in the center are completely sleek.