
That's 4.9 Penny Blossoms PER hour.
The Big Bang Theory Season 2, Episode 18

Based on the number of chirps
PER minute and the temPERature...
The Big Bang Theory Season 3, Episode 2

As PER your suggestion,
we're hanging out.
The Big Bang Theory Season 4, Episode 5

So let's plug in our 9.8 meters
PER second squared...
The Big Bang Theory Season 3, Episode 10

"Koo" from Koothrappali
and "PER" from CooPER.
The Big Bang Theory Season 9, Episode 12