There were 72,197 of them in 2014, up from 50,281 in 2000, according to the report by the Centers for Disease Control and Prevention. In 1980, they numbered about 15,000.

Even demographers seemed impressed. “There is certainly a wow factor here, that there are this many people in the United States over 100 years old,” said William H. Frey, the senior demographer at the Brookings Institution. “Not so long ago in our society, this was somewhat rare.”

Not only are there more centenarians, but they are living even longer. Death rates declined for all demographic groups of centenarians — white, black, Hispanic, female, male — in the six years ending in 2014, the report said.