This is because people in the past summarized and estimated that many old people would die at the ages of 73 and 84. There are also many historical celebrities who died at this age, such as Confucius and Mencius. But this statement has no scientific basis and is not obtained through accurate statistics.
There is a folk saying that has been circulating for a long time, called '73 and 84, the king of hell doesn't ask himself to go'. This sentence describes that the two age stages of 73 and 84 are the years when many old people die. If they survive, they can live a long time.
There are also many historical celebrities in China who died at the age of 73 and 84, such as Confucius and Mencius. In fact, there is no scientific basis for this statement, nor is it the result of accurate statistics.
It is more the result that people in the past summarized and estimated according to their own experience in life. There are also many old people who will buy spiritual animals such as turtle to release when buying this ridge, which means to accumulate blessings for themselves.