Need to add up all values of custom calculation

[CSibley]

I have been able to get a percentage calculation by dividing the values in the hours column by 35 in the Utilization Percentage column, but would like to add all those up to get a total percentage.  I'm relatively new to text mode and tried to Frankenstein things together from other columns.  Does anyone have the answer to getting the SUM to calculate at the top of the column?  NOTE: I fully realize this may be completely wrong but any help is appreciated.

aggregator.displayformat=double
aggregator.function=SUM
aggregator.valuefield=Utilization Percentage
aggregator.valueformat=doubleAsDouble
displayname=Utilization Percentage
textmode=true
valueexpression=DIV({hours},35)
valuefield=Utilization Percentage
valueformat=double
width=65