Complex sentence: As since the end of 1942 at the latest every partisan possessed such a weapon new members had to bring one along this means that about 10 to 15% of the victims of the German actions were partisans.
Split into simpler sentences: As since the end of 1942 at the latest every partisan possessed such a weapon. New members had to bring one along, meaning that about 10 to 15 percent of the victims of the German actions were partisans.