Grasshopper + Mosquito - Pedestrian Traffic Map

Hi guys,
I am new using the mosquito plug in and I want to do a pedestrian traffic map like the picture in this web page

I manage to do the grid and the circles that I color with gradient colors, but I want to have the circles in red more bigger than the cirles in yellow and this circles has to be more bigger that the circles in green, I tried with the multiple attractor points but the result is not the same as I want.
Please can someone know how to do the circles big and small as I need? Here I attach my gh file, so if someone can help me I am going to be so happy.

PEDESTRIAN FLOW 1ST SKETCH.gh (3.8 MB)
RHINO PEDESTRIAN 3.zip (6.3 MB)

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