As long as cows have been in existence, or the whole Bos primigenius species and subspecies have been in existence.
Helium is has been in existence since the beginning of the universe.
they have been in existence for 110 years since 1901.
He has been playing with the eagles his whole career. That started in 1999.
The IUPAC has been in existence since 1919. (93 years ago.)
long time
October 1920
since 1992
Since they where born
they have been here forever
88 years
The saxophone was patented in 1846.