calculate difference

[#1]

Hi guys,

I have a straight table where i need to find the difference between the values...

Product Name	Month	sum([Actual Value])
AHU	Jan	9368.44
AHU	Feb	8713.27
AHU	Mar	9637.76
Chiller	Jan	38690.87
Chiller	Feb	23797.2
Chiller	Mar	39456.88
Elavator	Jan	548.04
Elavator	Feb	487.34
Elavator	Mar	543.71

From above data i want to find difference between ( jan and feb) ie(8713.27 - 9368.44) values and then between(feb and mar) ie(9637.76 - 8713.27) values and so on...
what  expression i need to write....

thanks ,
hitesh

[tresB · Accepted solution]

Use above() function:

Above(Sum([Actual Value]))  - sum([Actual Value])

[#3]

thank you Tres qv