From Scientific American:
Almost everyone who ever lived was wretchedly poor. Famine, death from childbirth, infectious disease and countless other hazards were the norm for most of history. Humanity’s sad plight started to change with the Industrial Revolution, beginning around 1750. New scientific insights and technological innovations enabled a growing proportion of the global population to break free of extreme poverty.
Two and a half centuries later more than five billion of the world’s 6.5 billion people can reliably meet their basic living needs and thus can be said to have escaped from the precarious conditions that once governed everyday life. One out of six inhabitants of this planet, however, still struggles daily to meet some or all of such critical requirements as adequate nutrition, uncontaminated drinking water, safe shelter and sanitation as well as access to basic health care. These people get by on $1 a day or less and are overlooked by public services for health, education and infrastructure. Every day more than 20,000 die of dire poverty, for want of food, safe drinking water, medicine or other essential needs.
More here.