Officials say California has had the worst measles outbreak in 15 years, after at least 70 people were confirmed to have been infected. Below is a map of measles infections in the U.S. since 2009, tracked by the Global Health Program at the Council on Foreign Relations.
99 to 30
29 to 10
9 to 1
Note: As of Jan. 22, 2015; source: Council on Foreign Relations