Hi @Dicken 

This is not the correct way to calculate the average

avg = ( [avg ] + alist {x -1} ) / x

[avg] already contains the average of the previous x-1 values, not the sum of those values. 

You can't just add the next value to [avg] then divide by x 

The correct average calculation is either

avg = ([asum] + alist{x-1}) / x

or

avg =  asum / x

Regards

Phil