see also Human rights in Colombia Trade unions in Colombia were, until around 1990, among the strongest in Latin America. However the 1980s expansion of paramilitarism in Colombia saw trade union leaders and members increasingly targeted for assassination. As a result, Colombia has been the most dangerous country in the world for trade unionists for several decades. Between 1986 and 2010 over 2800 labor leaders were killed according to one source, and over 4000 according to others. Most assassinations were carried out by paramilitaries or the Colombian military; some were carried out by the guerrillas. In 2009 only around 4% of workers in Colombia were unionized. Major Union Federations History 1920-1946: Beginnings & Growth The development of the Colombian economy in the early 20th century was not as favorable for labor as compared to other Latin American countries, particularly when it came to the key export of coffee, which over the course of the 20th century came to dominate Colombian exports. Coffee, as an industry, was dominated by small growers, whose labor tended to come from the family-unit as opposed to the wage-laborer. While other industries which depend heavily on wage-labor did come to play a significant role in the development of the Colombian economy, these industries did not come to play as significant a role as in other Latin American countries. This doesn't mean that Colombia's early labor history was without incident. In fact, militant union activity flourished under the employment conditions of foreign firms such as New Jersey Standard Oil and the United Fruit Company, where workers had to migrate to formerly sparsely populated areas of rain forest for employment, and upon arriving found their living conditions to be in stark contrast to those of their foreign employers. A pattern of strikes & suppression emerged in the 1920s within these industries, employees of the former going on strike in 1924 & 1927 only to be met by government intervention, a large strike of the latter in 1928 being infamously ended by the Banana Massacre, where an unknown number of workers (from a few dozen to 3000) were killed after the government sent in military forces. The working conditions of these Colombian laborers have some famous representation in literature, Jose Eustacio Rivera's La Voragine depicting both the plight of the rubber worker & the rich biodiversity of the Colombian countryside, Gabriel García Márquez's One Hundred Years of Solitude &