From 1980 to 2002, over 62 million people visited Yellowstone National Park. During the same period, 32 people were injured by bears. Grizzly bear-inflicted injuries to humans in developed areas averaged approximately one per year during the 1930s through the 1950s, and four per year during the 1960s. Human injuries from black bears have decreased from averages of 46 per year from 1931 to 1969, to four per year during the 1970s, and less than one per year from 1980 to 2002. The chance of being injured by a bear while in the park is approximately one in 1.9 million. Eight known bear-caused human fatalities have occurred within the park since 1872, including two in 2011 and one in 2015. Seven of the eight bears were grizzlies, while the other was undetermined.