In the 1920s, about what share of miners in the Jharia and Raniganj coal mines were tribals?

1. Over 2,000 workers died in Indian coal mines yearly. 2. About 50 per cent of miners were tribals. 3. Contractors paid them miserably. _Source: syllabus Our Pasts III, Chapter 4, Tribals, Dikus and the Vision of a Golden Age._