This is a report put out by Impervia based on their 2019 DDoS attack study. Their analysis of attacks is based on data from 3,643 network layer DDoS attacks on websites using Imperva services from January 1, 2019 through December 31, 2019, and on 42,390 application layer attacks on websites using Imperva services from May 1, 2019 through December 31, 2019,