Let's style the result.
1. Go to the Layer Styling panel and make sure the neighbourhoods layer is active.
2. Change the renderer to Graduated and choose building percentage as Value.
3. Choose a colour ramp from white to red. Set the Mode to Natural breaks (Jenks) and use 5 classes.
4. Click Classify.
5. Now go to the Labels 
tab.
6. Change it from No labels to Single labels.
7. Choose buurtnaam for Value.
8. Go to the Formatting 
tab.
9. At Wrap on character type a space to split words to different lines for a better fit in the polygons.
10. Evaluate the result.
