The chart is set by default to show average data (per 10 results).
Analyzing averages (per 2, 3, 5, or 10 results) will help you spot useful trends. Analyzing every page separately will help you notice deviations.
If you want to see each website one-by-one or look deeply on the TOP 10 performers, switch off the button.
Or set your own averages as presented below: