Although the twentieth century had more than its fair share of horrors, it also was an era of incredible development. Modern medicine, sanitation, and agriculture helped billions of people live longer, healthier lives.

The Gapminder Foundation is dedicated to using statistics to inform people about the ways in which our world has changed and continues to change. The coolest tool on its website is Gapminder World, which allows anyone to make animated graphs showing how different statistics — ranging from carbon dioxide emissions, to income inequality, to the ratio of boys to girls in school — have changed in different countries over time.

We made a graph to show how child mortality and life expectancy have changed around the world since 1950 (animated below; interactive version here).

The countries are color-coded by region: red is East Asia and the Pacific, orange is Europe and Central Asia, yellow is the Americas, green is the Middle East and North Africa, light blue is South Asia, and dark blue is Sub-Saharan Africa.

Over the last fifty years, global life expectancy has risen and child mortality rates have dropped, as can be seen by the overall trend of countries moving down (lower child mortality) and to the right (higher life expectancy).

In 1950, 59 countries had child mortality rates of more than 200 per 1,000 live births — in those countries, more than one fifth of all children died before the age of five. In 2012, no countries had child mortality rates that high.

These two measures are closely related. Child mortality is a huge factor in overall life expectancy — a large number of children dying can cancel out many people living to old age, and bring down the average lifespan.

Although the general global trend over the last sixty years has been towards better health, it is possible to see a number of disastrous moments in the image. At the end of the 1950s and beginning of the 1960s, China — the large red circle — sees a brief regression, with life expectancy dropping and child mortality rates going up. This coincides with the Great Leap Forward and the subsequent famine.

Similarly, the Cambodian genocide under the Khmer Rouge can be seen as the small red circle swinging up and to the left in the early and mid 1970s.

Here's a link to the interactive version of the graph.