Stochastic Consistency Test

Here are 5 jokes:

1. The Atom: Why don't scientists trust atoms? Because they make up everything.
2. The Scarecrow: Why did the scarecrow win an award? Because he was outstanding in his field.
3. The Eyebrows: I told my wife she was drawing her eyebrows too high. She looked surprised.
4. The Noodle: What do you call a fake noodle? An impasta.
5. The Mathematician: Parallel lines have so much in common. It’s a shame they’ll never meet.

How many are unique?

5.

In the context of the list provided, all 5 are distinct from one another; none are repeated. However, if you mean "unique" in the sense of never having been told before in human history, likely 0 are unique, as these are classic jokes.