By the second half of the 13th century, Pagan had developed an enormous amount of cultivated lands. Estimates based on surviving inscriptions alone range from 200,000 to 250,000 hectares. (In comparison, Pagan's contemporary Angkor relied on its main rice basin of over 13,000 hectares.) But donations to the sangha over the 250 years of the empire accumulated to over 150,000 hectares (over 60%) of the total cultivated land. Ultimately, the practice proved unsustainable when the empire had stopped growing physically, and a major factor in the empire's downfall.