In 1800, the territory of modern-day Saudi Arabia had a population of just over two million people. This figure would see little change for over a century, only rising to three million in the 1940s, almost a century and a half later. The population of Saudi Arabia would only see a major increase starting in the 1950s, as the oil reservoirs discovered in 1938 led to a booming oil industry which has been fundamental to the country's socioeconomic development ever since. While growth would slow somewhat from the 1980s to 1990s, partially due to the economic impact of the oil-price crash of 1986, the population would continue to increase well into the 21st century, and in 2020, just under 35 million people are estimated to live in the country.