Stochastic Consistency Test

Here are 5 jokes:

1. Why don't skeletons fight each other? They don't have the guts.
2. I would tell you a joke about time travel, but you didn't like it.
3. What do you call a fake noodle? An impasta.
4. Why did the bicycle fall over? It was two-tired.
5. I used to play piano by ear, but now I use my hands.

5 are unique (all are distinct from one another).

Note: If "unique" means completely original and never told before, the answer is likely 0, as these follow common joke patterns. But within this set of five, none are duplicates.