The life expectancy for men is less than 81 years. For women, it is not longer than 86.
The average marriage now lasts just seven years, so the lifespan and marriage of this couple might be nothing short of a miracle.
"Everybody wants to know the secret," Ralph Riggs said, laughing.
Ralph and his sweetie, Mary Lou Riggs, are high school sweethearts who have changed little since their days of walking the halls, hand in hand.
"We both have arthritis. It's not much fun to hold hands anymore," Mary said, smiling.
The Riggs tied the knot when she was 19 and he was 21 years old.
"1933, Nov. 4," Mary rattled off.
She is now 98. He will be 100 years old in less than 10 days. They've been married 79 years.
"He was a prize to get a hold of," Mary said, grinning.
How did Mary snag the star football player all those years ago? What made Ralph pop the question.
"Was it my father? Just kidding," Mary said.
The two have lived through 17 presidents.
"William Howard Taft was president when I was born," Mary said.
They have seen changes like you wouldn't believe.
"Charles Lindbergh flew the Atlantic in 1927," Ralph said.
"We didn't know how to spell television. There was no such word," Mary added.
"You could get a quart of milk, pound of bacon and loaf of bread for a dollar. When we first moved to Pittsburgh (before moving to Texas), I made $24.95 a week," Ralph said.
They are like walking history books with a long love story to tell. Ralph still likes it when Mary kisses him goodnight. He still mows the pasture on his tractor and she still drives herself 17 miles to water exercise twice a week.
"We both drive. We both have our license," Mary said.
They credit staying active and eating right for living long lives. Yes, they have cell phones and their six kids are their computer.
"We can get any information we need from them."
Their youngest child is now 77-years-old. They have 18 grandchildren and 24 great-grandchildren.
The Riggs said having trust, respect and friendship for one another is the key to staying married.
"Are we in love?" Mary asked her husband.
"Well, I guess that's what you call it," Ralph answered, laughing.
They said love and marriage include accepting the responsibility and never backing out on your spouse and kids.