A young boy from the remote Turkana tribe in Northern Kenya plays to the camera as villagers wait their turn to see if they will be selected for food aid by other villagers at Kokuru. Getty Imags/Christopher Furlong There are dozens of ways to measure humanity's progress over the last couple centuries, including reductions in childhood mortality, disease, and hunger.

But one of the most striking signs is the progress we've made in combatting extreme poverty.

In honor of International Day for the Eradication of Poverty, observed on October 17, Oxford economist Max Roser has highlighted the sections on his blog, Our World in Data, that deal with the global fight to uplift the extremely poor.

He recently tweeted one of the more heartening facts: "Newspapers could have had the headline 'Number of people in extreme poverty fell by 137,000 since yesterday' every day in the last 25 years."

The World Bank defines extreme poverty as living on less than $1.90 a day. In 2015, roughly 705 million people were living in extreme poverty.

This figure may seem high, but Roser points out on his blog that the trend of eradicating extreme poverty is nothing short of remarkable, given that the total number of extremely poor people today is three times lower than it was in 1970. Even more striking, in 1820, approximately 1 billion of the world's 1.1 billion people lived in extreme poverty.

"Unfortunately, the slow developments that entirely transform our world never make the news, and this is the very reason why we are working on this online publication," Roser wrote on his blog with fellow Oxford economist Esteban Ortiz-Ospina.

Poverty isn't just disappearing at the extremes. It's also fading among people living in moderate poverty, or less than $3.10 a day. Meanwhile, the population of people living with $10 or more a day has been growing since around the year 2000.

One of the ongoing challenges is awareness, Roser explained. People don't seem to realize that poverty rates are actually going down — poverty seems like more of a fixed problem, for which there is no end in sight.

But the World Bank has made it its goal to end extreme poverty by 2030. Roser has said the goal may be too ambitious to hit, but he forecasts the rate could go as low as 4%. Compared to the rate of 42% in 1981 and nearly 100% in the 19th century, 4% is progress by any definition.