6 years
long, long ago.
Since the first pokemon.
Since a few months
The Alamo has been there since 1718.
They have been out since 1984
1919
since 1891 since 1891
Really? How long has it been since you were in kindergarten?
since 1883
As of 2010, it has been 3 years since their last appearance.
Since 1999
Since 1905