Bizarre looping problem

This is bizarre. I basically want to get the average of the last x amount of bars.

Even when I set the loop to 1 it doesnt calculate properly.

Pseudo code should be something like this:

1. Go back 10 bars and add up all the bar ranges
2. Divide the total amount by the lookbackperiod when the loop has completed

The calculations are completely incorrect. Im stuck as I cant see anything wrong with the code. Line 15 seems to be the problem but why?

Note: I am running this on the m6e futures which is why I multiply by 10000

//Grantx

defparam drawonlastbaronly=true

//--- settings
Loockbackperiod = 10
//--- end of settings

RngeSum = 0
largestBar = 0
FOR i = 0 TO Loockbackperiod DO
if (Range[i]>largestBar) THEN
largestBar = Range[i]
ENDIF
RngeSum = RngeSum + Range[i]
NEXT
//RngeSum = Round((RngeSum / Loockbackperiod)*10000)
RngeSum = Round(RngeSum*10000)
largestBar = largestBar*10000

drawtext("                                                                                            ABR(#Loockbackperiod#) = #RngeSum# ¬ LB = #largestBar#",barindex,High,Dialog,Standard,10) coloured(0,0,255)

RETURN