Lets $\phi(n)$ is Euler's phi function. Let's define error term $$ d(n) = {E(n) \over n} = {1 \over n} \left(\sum_{i\le n}\phi(i) - {3 n^2 \over \pi^2}\right) $$

Is it known that asymptotic of mean (and median) of the first N values $d(n)$ is equal to 3/\pi^2?

$$ \lim_{N\to\infty} {\sum_{n=1}^N d(n) \over N} = 3/\pi^2 $$

I can't extract this fact from the papers Oscillations of the remainder term related to the Euler totient function and The Existence of a Distribution Function for an Error Term Related to the Euler Function.

Update: bug fixed - the limit is not 1 but 3/π^2, as noticed below by GH from MO.