RTF values not summing up

I have been trying to calculate the sum of values group by specific element and person number in the RTF template, but unfortunately, I have been unable to achieve the desired result. It seems that the formula or function I am using is not working correctly. 

1st formula i used

<?if:REPORTING_NAME = 'FIT Gross'?>

<?sum(RUN)?>

<?end if?>

Output: -- the person has 2 FIT Gross, my expected output is 15497.72 but it is showing as 2 record.

FIT Gross 

11267.72

4230.8

2nd formula i used

<?sum(//RUN[../REPORTING_NAME = 'FIT Gross'])?>

Output: --it is adding all FIT Gross including other persons FIT Gross, my expected output is 15497.72, sum of 11267.72 and 4230.8.