Hascol Petroleum Ltd. is interested in estimating its sustainable sales growth rate. Last year, revenues were Rs. 2.5 million; net profit was Rs. 150,000; investment in assets was Rs. 750,000; payables and accruals were Rs. 100,000; and stockholders equity at the end of the year was Rs. 450,000 (i.e., beginning-of-year equity of Rs. 400,000 plus retained profits of Rs. 50,000). The venture did not pay out any dividends and does not expect to pay dividends for the foreseeable future. Estimate the sustainable sales growth rate for Hascol Petroleum based on the information provided in this scenario.