• The population of people 100 and older represent fewer than two per 10,000 people.
• Centenarians represent 19 of 10,000 people who are 70 and older.
• More than half -- 62.5 percent -- are 100 or 101, while roughly 92 percent are ages 100 to 104.
• Supercentenarians -- those ages 110 and older -- represent 0.6 percent of the centenarian population.
Source: U.S. Census Bureau
It was the year the Lusitania made its maiden voyage from Liverpool to New York. The Titanic wouldn't even be under construction for two years. Oklahoma became the newest state: No. 46. Rudyard Kipling was awarded the Nobel Prize for Literature. And Rosa Lee Walker was born on Fredonia Mountain.
It was 1907. Today, the ships, Kipling and even Oklahoma's fleeting title are gone. But not Rosa Lee.
Rosa Lee Walker Blevins turned 105 last week in her home of 56 years on Signal Mountain, and she's quick to smile and share her secret of longevity.
"My children, my grandchildren, my great-grandchildren and my great-great-grandchildren. My family," she said.
Blevins is one of only about 53,000 people in the nation -- about 900 in Tennessee -- who are 100 or older, according to figures from the U.S. Census Bureau.
That's a tiny proportion of the nation's total population -- representing fewer than two centenarians for every 10,000 people of younger ages. And despite rapid health care and technology advances, their ranks are growing slowly.
There were 53,364 centenarians in the United States in 2010, representing only 1.73 per 10,000 people in the total population. This proportion has increased only slightly since 1980, when it was 1.42 per 10,000.
Even among oldsters, people who live to 100 and beyond still are rare.
And they are overwhelmingly female. For every 100 centenarian women, there are only 20.7 centenarian men.
Charles Hess, administrator of Alexian's Health and Rehabilitation Center, said three things contribute to the long lives of these folks: Access to good health care, good attitudes and family support.
"It seems to be a common thread. If they have access to good medical care through the years, then they seem to have a better quality of life for longer," Hess said. And the supportive family contributes to their good outlook.
When Rosa Lee was born, the average life expectancy in the U.S. was 47 years. More than 95 percent of all births in the U.S. took place at home.
The average wage in the U.S. was 22 cents an hour.
Only 14 percent of the homes in America had a bathtub, and only 8 percent had a telephone.
Electricity didn't come to Tennessee -- where Rosa Lee has lived her whole life -- until she was at least in her 20s.
Today, Rosa Lee lives in the same house she and her husband and sons built on the back side of Signal Mountain in 1956, clearing timber from a 25-acre farmstead. Her husband, Chester, died several years ago.
She says she has had five children, 10 grandchildren, 18 great-great-grandchildren, and four great-great-great-grandchildren,
Son Don Blevins has moved in with her to help keep her company, and she spends most of her time quilting and watching television.
Last week, the centenarian -- still a beautiful woman -- primped as visitors settled in to see her.
"Everybody asks where are my wrinkles," she said with a sly grin. "I say, 'Well, am I supposed to have some?'"
As she talked, Don climbed onto her motorized scooter to turn it in close quarters and ride it out of the way, while his brother Doug teased him that their mom did a better turning job.
"She's like Mario Andretti on that thing," Doug said, laughing.
She doesn't like to dwell on life's sad moments, like wars or losing two of her five children to cancer.
Her father was a coal miner and her mother was a mining company postmaster.
The working mother would take her tiny baby girl to work with her and place her where she could watch her sleep in a box her father's tall work boots had come in.
The customers would all talk and coo with "my little Rose," she tells her children.
Her daughter, Martha Hillis, said Rosa Lee uses quilting to keep one foot squarely planted in her history, but at the same time she enjoys the technological wonders of today -- especially television.
"Mom loves quilting and the [Atlanta] Braves," Martha said. "Even when they play on the West Coast and start time is so late, she will sit up and watch every minute of the game. And the closer the score, the faster that needle will fly."
Hess believes the gamut of changes that have occurred in centenarians' lives helped make them who they are.
A self-proclaimed history buff, he says he loves talking with the oldsters about the differing times in their lives.
"In the past 100 years -- that's an awful lot of things that have changed. They give you a perspective that you can't get with someone who is 50, 60 or 70 years old."
Today's centenarians lived through the Depression and grew up hard. They went through the world wars.
"That defines who you are a lot of times," Hess said. "They had to grow up in a certain way to survive."