Surface output data

Hi experts,

I want to extract integrated surface output data (like total heat flux through the output surface) from a given geometry using udfGetOsiData(). I have attached the geometry, along with the code herewith.

I was able to write to a file, but I could see a large number of data (and lines) even for a single time step. Can anyone tell what's going on here and why I am getting large number of data lines for an integrated result?

Another thing is when I write all time steps, I get tremendous number of lines. Do I need to sum those data lines on my own to get an integrated result?