 By May 2010, more than 22,000 "Stolpersteine" had been set in 530 European cities and towns, in eight countries which had formerly been under Nazi control or occupied by Nazi Germany.By July 2010 the number of "Stolpersteine" had risen to more than 25,000, in 569 cities and smaller towns.By June 2011 Demnig had installed 30,000 "Stolpersteine".