The input x(t) and the output y(t) of an LTI system are related as, y(t) = x(t + 1) - x(t - 1).  A white noise process with a two-sided power spectral density of 4 μW/Hz is passed through an ideal low pass filter whose cut off frequency is 0.5 Hz and the resulting process is applied as input x(t) to the above described LTI system. The average power of the corresponding output process y(t) will be ______.