Confusion of MAPE/MPE calculation

I have some confusion of MAPE/MPE calculation, since the source is different, the methodology is also different, indeed confused.

For MAPE,
1)average of absolute error/actual demand
2)sum of absolute error/sum of actual demand

For MPE,
1)average of errors/actual demand
2)sum of errors/sum of actual deman

which one (more) make sense?