According to Angus Maddison, between the years 1000 and 1500, India's GDP, of which the sultanates represented a significant part, grew nearly 80% to $60.5 billion in 1500. However, these numbers should be viewed in context: according to Maddison's estimates, India's population grew by nearly 50% in the same time period, amounting to a per-capita GDP growth of around 20%. World GDP more than doubled in the same period, and India's per-capita GDP fell behind that of China, with which it was previously at par. India's GDP share of the world declined under the Delhi Sultanate from nearly 30% to 25%, and would continue to decline until the mid-20th century.