The longer something has been around, the more likely it will continue to be around.
The mathematical version is a simple formula. Predicted life span is double the length of past life span-
L=2(P)
or
Y=2(X)
if you wanted to use X and Y
-If something has been around 1 year, it should be around 1 more year
-If something has been around 2 years, it should be around 2 more year
-If something has been around 3 years, it should be around 3 more years
-If something has been around 50 years, it should be around another 50
You can imagine how quickly something goes form 2-4-8-10-12, so on and so forth
To Note:
--This applies only to those things which remain in the original (or very close to it) iteration. Ie, things that dont change from the original form.
So example, something like BOOKS, which have not fundamentally changed in any way the past 500 years, we can presume they would be around another 500.
Or say something like the Barbell, which has been in popular use for about 100 years, we can presume another 100 years.
Or even with FOOD; pasta has been around thousands of years, pasta is very unlikely to "go away" anytime soon.