Colombia asked Germans who were on the U.S. blacklist to leave and allowed Jewish refugees in the country illegally to stay. The Jewish population increased dramatically in the 1950s and 1960s, and institutions such as synagogues, schools and social clubs were established throughout the largest cities in the country. The changing economy and wave of kidnappings during the last decade of the 20th century led many members of Colombia's Jewish community to emigrate. Most settled in Miami and other parts of the United States. Successes in the nation's Democratic security Policy has encouraged citizens to return; it has drastically reduced violence in the rural areas and criminality rates in urban areas, as well as in spurring the economy. The situation in Colombia has improved to the extent that many Venezuelan Jews are now seeking refuge in Colombia. In the early 21st century, most of the Jews in Colombia are concentrated in Bogotá, with about 20,000 members, and Barranquilla, with about 7,000 members. Large communities are found in Cali and Medellín, but very few practicing Jews. Smaller communities are found in Cartagena and the island of San Andres. There are 14 official synagogues throughout the country. In Bogotá, Jews each run their own religious and cultural institutions. The Confederación de Asociaciones Judías de Colombia, located in Bogotá, is the central organization that coordinates Jews and Jewish institutions in Colombia. In the new millennium, after years of study, a group of Colombians with Jewish ancestry formally converted to Judaism to be accepted as Jews according to the halakha. Costa Rica The first Jews in Costa Rica were probably conversos, who arrived in the 16th and 17th centuries with Spanish expeditions. In the 19th century Sephardic merchants from Curaçao, Jamaica, Panama and the Caribbean followed. They lived mostly in Central Valley, married local women, and were soon assimilated into the country's general society. Most eventually gave up Judaism altogether. A third wave of Jewish immigrants came before World War I and especially in the 1930s, as Ashkenazi Jews fled a Europe threatened by Nazi Germany. Most of these immigrants came from the Polish town Żelechów. The term Polacos, which was originally a slur referring to these immigrants, has come to mean door-to-door salesman in colloquial Costa Rican Spanish. The country's first synagogue, the Orthodox Shaarei Zion, was built in 1933 in the capital San José (it is located along 3rd Avenue and 6th