Launch

Start directly with the "Assistant for Thematic Maps"".

Select type

Select "Graduated Symbol" and click Next.

Layer & Data Field

Select the layer "FTTH_Locations" and the data field "Total_Flats".

Note: Only number fields are offered!

Define Areas

Define the symbol and its size for the reference value.

Define style

Now switch to the "Styles" tab.

Now define a style.

Style for reference value

Formula

Now define how the symbol size should change proportionally to the value.