The dies coming together is a mishap or error that creates a change in the die, the coins produced by those clashed dies are a die stage. The 1942/1 is a variety, the die was like that when it started striking coins. The 37 D 3 leg and 1922 (P) cent are die stages
Considering the clashing of the dies is not a planned even but rather an accident, and something that can happen at any time, with tens of millions of ASE's made each year I would suspect that if you looked for them you could probably find them for every year.