Use the BubbleSize formula to define the size of each bubble.
Formula contract. The formula runs for each bubble in the current record context. Its numeric Result is interpreted as a diameter; the graph uses half of the value as the bubble radius. A NULL, empty or invalid formula uses radius 1. Use a positive value because the formula does not validate zero or negative sizes.
The formula has no dedicated Argument_ variables. It can use the normal MathParser values available for the current record.