 During December and January, Main Force raids killed hundreds of people and rendered between 20,000 and 80,000 homeless each night.In 1982, Laurenz Demps collated loss data using the damage reports of the Berlin police commissioner ("Polizeipräsident") issued after each air raid, descriptions of losses and damage indicated by houses and distributed to 100–150 organisations and administrations busy with rescue, repair, planning and other matters, against reports of the main bureau for air raid protection ("Hauptluftschutzstelle") of the city of Berlin, which issued more than 100 copies with variable frequency, each summarising losses and damage by the number of air raids; the war diary of the air raid warning command ("Luftwarnkommando" – Wako Berlin), a branch of the "Luftwaffe" and other sources.Demps wrote that 7,480 people had been killed, 2,194 people were reported missing, 17,092 were injured and 817,730 Berliners made homeless.