PV on Solar Tracker vs roof installed and 46% of difference.
Same period, same city, 6.5kWp (20 panels on two trackers) vs 9.9 kWp (33 panels installed on roof).
Each 1kWp installed on the tracker produced 62.56 kWh per week, total 426.14 kWh.
Each 1kWp installed on the roof produced 44.96 kWh per week, total 445.14 kWh.
That numbers shows that installation on tracker was 46% more effective.
From the other side to generate the same amount of electricity you need 46% more panels on the roof then on the tracker.