For some other stats, I've been looking at ADS-B traffic on Flightaware, I'm seeing a drop from about 160 flights a day before the lockdown to around 30 a day now. The Flightaware guys have sent out instructions on how to change the warning threshold because many feeders are now getting (false-positive) outage alerts because of the drop in traffic.
Edited to add: Hmm, just noticed that AirborneKiwi is offline, he's a GZ member from memory...