The last public analysis was done in 2010 by RIPE and APNIC. At the time, 1.1.1.0/24 was 100 to 200Mb/s of traffic, most of it being audio traffic. In March, when Cloudflare announced 1.0.0.0/24 and 1.1.1.0/24, ~10Gbps of unsolicited background traffic appeared on our interfaces.