Yes, you have to install performance graphs. Please see the FIRST post of this thread.
ADS-B Receiver Project Setup Scripts
Since you have burnt Piaware 3.1.0 image to your microSD card, it already has dump1090-fa. While running the script in above thread, choose NO to BOTH dump1090-mutability and dump1090-fa.
The graphs are installed if “Web Portal” is slected in the options at the begening of installation process.