Myanmar had a murder rate of 15.2 per 100,000 population with a total of 8,044 murders in 2012. Factors influencing Myanmar's high murder rate include communal violence and armed conflict. Myanmar is one of the world's most corrupt nations. The 2012 Transparency International Corruption Perceptions Index ranked the country at number 171, out of 176 countries in total. Myanmar is the world's second largest producer of opium after Afghanistan, producing some 25% of the world's opium, and forms part of the Golden Triangle. The opium industry was a monopoly during colonial times and has since been illegally operated by corrupt officials in the Burmese military and rebel fighters, primarily as the basis for heroin manufacture. Myanmar is the largest producer of methamphetamines in the world, with the majority of ''Ya ba'' found in Thailand produced in Myanmar, particularly in the Golden Triangle and northeastern Shan State, which borders Thailand, Laos and China. Burmese-produced ''ya ba'' is typically trafficked to Thailand via Laos, before being transported through the northeastern Thai region of Isan.