Childhood cancer deaths in the United States have declined six-fold over the last seventy years— Childhood cancer deaths in the United States have fallen dramatically over time, as shown in the chart. It presents annual cancer death rates in children under five years old. There has been a six-fold decline since the 1950s. This progress reflects decades of collaboration between scientists, clinicians, and public health workers. One major success story has been in treating acute lymphoblastic leukemia, a common form of leukemia in children: researchers identified genetic mutations that caused the disease, making it possible to develop targeted chemotherapy drugs that have greatly improved survival. Surgeries, bone marrow transplants, and other treatments have also played a role. We’ve also seen big improvements for other blood cancers, such as lymphomas and multiple myeloma, though progress has been slower for cancers of the brain and nervous system. (This Daily Data Insight was written by @salonium.)

In 1820, 8 in 10 people worldwide lived on less than $1.90* a day, an extremely low poverty line. 200 years later, it had dropped to 1 in 10 people. How do we know how many people were in poverty 200 years ago? Where do these numbers come from? Learn the answers in our article "How do we know the history of extreme poverty?": *This is measured in international-$ at 2011 prices, which means it's adjusted for inflation and differences in the cost of living between countries. It's the equivalent of what $1.90 could buy in the US in 2011.