Because the total number of consumers increased every month, the monthly sales are standardized as monthly sales per 1,000 consumers. Exclusive, primary, secondary and rare use are defined as 10–12 (blue shaded), 5–9 (green), 2–4 (orange) and 0–1 (red) 14.2 kg cylinder(s) purchased in one year by an average rural household of five members. The baseline all-India (Urban + Rural) average purchase was 7.3 cylinders per household in 2015–2016 (blue dashed line). Reproduced with permission from Kar, A., Pachauri, S., Bailis, R. & Zerriffi, H. Nat. Energy 4, 806–814 (2019); Springer Nature Ltd.