World War II. Of these, 160,000–180,000 were killed as a part of the Holocaust. Those that remained in Germany went into hiding and did everything they could to survive. Commonly referred to as "dashers and divers," the Jews lived a submerged life and experienced the struggle to find food, a relatively secure hiding space or shelter, and false identity papers while constantly evading Nazi police and strategically avoiding checkpoints. Non-Jews offered support by allowing the Jews to hide in their homes but when this proved to be too dangerous for both parties, the Jews were forced to seek shelter in more exposed locations including the street. Some Jews were able to attain false papers, despite the risks and sacrifice of resources doing so required. A reliable false ID would cost between 2,000RM and 6,000RM depending on where it came from. Some Jews in Berlin looked to the Black Market to get false papers as this was a most sought-after product following food, tobacco, and clothing. Certain forms of ID were soon deemed unacceptable, leaving the Jews with depleted resources and vulnerable to being arrested. Avoiding arrest was particularly challenging in 1943 as the Nazi police increased their personnel and inspection checkpoints, leading to 65 percent of all submerged Jews being detained and likely deported. On May 19, 1943, only about 20,000 Jews remained and Germany was declared judenrein (clean of Jews; also judenfrei: free of Jews). Persistence of antisemitism During the medieval period antisemitism flourished in Germany. Especially during the time of the Black Death from 1348 to 1350 hatred and violence against Jews increased. Approximately 72% of towns with a Jewish settlement suffered from violent attacks against the Jewish population. Regions that suffered from the Black Death pogroms were 6 times more likely to engage in antisemitic violence during the 1920s, racist and fascist parties like the DNVP, NSDAP and DVFP gained a 1.5 times higher voting share in the 1928 election, their inhabitants wrote more letters to antisemitic newspapers like "Der Stürmer", and they deported more Jews during the Nazi reign. This is due to cultural transmission. According to a study by Nico Voigtländer and Hans-Joachim Voth, Germans who grew up during Nazi rule are significantly more antisemitic than Germans born before or after them. In addition, Voigtländer and Voth found Nazi antisemitic indoctrination was more effective in areas with pre-existing widespread antisemitism. A simple model of cultural