Some level of unity returned in the Riau region for the first time after 150 years, with the creation of the Sijori Growth Triangle in 1989. But while bringing back some economical wealth to Riau, the Sijori Growth Triangle somewhat further broke the cultural unity within the islands. With Batam island receiving most of the industrial investments and dramatically developing into a regional industrial centre, it attracted hundreds of thousands of non-Malay Indonesian migrants, changing forever the demographic balance in the archipelago. A number of studies and books have detailed the growing violence and concern about identity and social change in the archipelago. As the Malay, who were once the dominant ethnic group in the islands, have been reduced to about a third of the population, primarily as a result of immigration from elsewhere in Indonesia, they feel that their traditional rights are threatened. Similarly, the immigrants have felt politically and financially suppressed. Both of these causes have led to increased violence. Piracy in the archipelago is also an issue. There have been various attempts at both independence and autonomy for this part of Indonesia since the founding of Indonesia in 1945.