Custom Measure for Year over Year Variance

I have to sort a report based on a year over year variance and am trying to create a custom measure to do so but not getting any results. I got the following two formulas to have but it doesn't return any values. Does anyone have an example of doing a custom measure involving variance or percent variance calculations?

First try:

IIF([%ACCOUNTDIM%].CURRENTMEMBER.PROPERTIES("ACCTYPE")="INC" OR [%ACCOUNTDIM%].CURRENTMEMBER.PROPERTIES("ACCTYPE")="EXP",CLOSINGPERIOD(([%TIMEDIM%].MONTH-[%TIMEDIM%].CURRENTMEMBER.LAG(12)/[%TIMEDIM%].CURRENTMEMBER.LAG(12)):CLOSINGPERIOD([%TIMEDIM%].MONTH,[%TIMEDIM%].CURRENTMEMBER),MEASURES.[PERIODIC]),MEASURES.[PERIODIC])

Second Try:

IIF([%ACCOUNTDIM%].CURRENTMEMBER.PROPERTIES("ACCTYPE")="INC" OR [%ACCOUNTDIM%].CURRENTMEMBER.PROPERTIES("ACCTYPE")="EXP",({MEASURES.[PERIODIC],[%TIMEDIM%].MONTH}-{MEASURES.[PERIODIC],[%TIMEDIM%].CURRENTMEMBER.LAG(12)})/{MEASURES.[PERIODIC],[%TIMEDIM%].CURRENTMEMBER.LAG(12)},1)

Please let me know if anyone has any suggestions or input. I know that logic is an option here but the client currently has a pretty basic app and I don't want to make them run logic for the sake of a single report.

Thanks,

Ken