Billionaire Microsoft co-founder Bill Gates says you need to know three facts to better understand the world.

Those statistics are the global rate of childhood deaths, the fertility rate and the number of people who escape extreme poverty.

The facts come from Oxford economist Max Roser, the founder of the data and statistics website, OurWorldInData.org.

“One of my favorite websites is OurWorldInData.org. Based at the University of Oxford, it uses statistics — on everything from health and population growth to war, the environment, and energy — to give you phenomenal insight into how living conditions are changing around the world,” says Gates in a post published on his blog Tuesday. “I asked its founder, Oxford economist Max Roser, to share three facts from the site that everyone should know.”

Roser says memorizing a few statistics gives you a framework to more accurately understand the world.

“Yes, for some details, it makes sense to just search for them when you need them. But for the large global developments, it is important to know some basic statistics that describe living conditions currently and the direction of change that we have seen over the past few decades,” says Roser in a piece published on the Gates Notes blog.

“Knowing the facts on global changes gives you the context for the daily news and allows you to make sense of new information that you learn. And it must be the basis for political debate, so that we can discuss what we should and shouldn’t do as a society.”

Here’s what Gates and Roser say you need to know:

1. Annual childhood deaths have fallen by more than half since 1960

Each year, 5.6 million children under the age of five die. That’s 15,500 deaths per day and 11 deaths of children per minute, according to data from the UN. In the 1950s and 1960s, 20 million children were dying every year, according to the same data set.

“One key reason why we struggle to see progress in the world today is that we do not know how very bad the past was. Both are true at the same time: The world is much better than in the past and it is still awful,” says Roser.

“To bring this to mind I need to know both statistics: When someone says we can sit back and relax because the world is in a much better place, I point out that 11 children are still dying every minute. We cannot accept the world as it is today. And when I feel hopeless in the face of this tragedy, I remember that we reduced annual child deaths from 20 million to 5.6 million in the last 50 years,” writes Roser.

2. The average number of children born per woman per year is falling

In the last 50 years, the global fertility rate, or the average number of children every woman in the world has, has fallen from five to less than 2.5, Roser says. That means the rate of population growth has gone from 2 percent a year to just over 1 percent per year.

Availability of contraceptives and access to education and higher quality jobs affect fertility rates, says Roser. So too does child mortality rates.

“Improvements in conditions for women and the health of children have driven a rapid reduction in fertility rates across the world,” says Roser. “The statistic that I remember on population growth is the one that tells me that rapid population growth is coming to an end in this century.”

Why is that important? “The problem is that the population is growing the fastest where people are less able to deal with it,” Gates explained in a 2012 blog post, so there is an inability to feed, educate, employ and protect the environment.

3. More than 100,000 people a day have escaped extreme poverty in recent decades

Between 1990 and 2015, 137,000 people left “extreme poverty” each day, says Roser.

Someone is defined as living in “extreme poverty” if they live on the equivalent of less than about $1.90 per person per day, as determined by the World Bank.

Today, 706 million people in the world live in extreme poverty. In 1990, 1.86 billion people lived in extreme poverty. That means the number of people living in extreme poverty has fallen to one in 10 people from one in three.

“When you ask people whether the world is making progress against extreme poverty, the majority of us believe things are getting worse — that the number of people in extreme poverty in the world is rising,” says Roser. “The opposite is true. Both the number and the share of people in extreme poverty is falling.”

Though the number of people living in extreme poverty is still “unacceptably large,” says Roser, “we should also know that the trend is moving in the right direction. The number of people in extreme poverty is falling. It is possible to end extreme poverty.”

Knowing these statistics is a reason feel optimistic, says Roser. “The statistics on global change over time tell us that it is possible to work for a better world. The number of child deaths is dropping. The challenges of rapid population growth will not continue indefinitely. And the number of people in extreme poverty is falling,” he says. “Our past successes should encourage us to work for more progress.”

Gates also advocates holding onto an optimistic view of the world.

“I’m not trying to downplay the work that remains. Being an optimist doesn’t mean you ignore tragedy and injustice. It means you’re inspired to look for people making progress on those fronts, and to help spread that progress,” Gates wrote as the guest editor for Time magazine in January.

“To some extent, it is good that bad news gets attention. If you want to improve the world, you need something to be mad about,” he said. “But it has to be balanced by upsides. When you see good things happening, you can channel your energy into driving even more progress.”