“Why did the banana go to the doctor?”/“It wasn’t peeling well.”

A banana pun is:
 
Q: Why did the banana go to the doctor?
A: It wasn’t peeling well.
 
The joke has been cited in print since at least 1990.
 
   
Google Books
Super Sick Jokes and Riddles
By Joseph Rosenbloom and Sanford Hoffman
New York, NY: Sterling Publishing Company, Inc.
1990
Pg. 16:
Why did the banana see the doctor?
It wasn’t peeling well.
 
26 March 1996, Sun Sentinel (Fort Lauderdale, FL), “Jokes on You!,” pg. 10E:
Why did the banana see the doctor?
It wasn’t peeling well.
 
Google News Archive
15 April 1996, The Register-Guard (Eugene, OR), jokes from Kidsday (Newsday), pg. 3D, col. 2:
Why did the banana see the doctor?
It wasn’t peeling well.
 
25 October 1998, Los Angeles (CA) Times, “Laugh Lines: Pint-sized Punch Lines,” pg. 2:
Why did the banana go to the hospital? Because it wasn’t peeling well. (Elizabeth Schofield, 6, Torrance, Hickory Elementary)
 
Google Books
Super Silly Riddles
By Charles Keller
New York, NY: Sterling Publishing Company, Inc.
2002
Pg. 69:
Why did the banana go to the doctor?
It wasn’t peeling well.
 
Google Books
A Joke a Day Keeps the Doctor Away
By Bob Phillips
Eugene, OR: Harvest House Publishers
2008
Pg. 8:
Q: Why did the banana go to the doctor?
A: It wasn’t peeling well.
     
Google Books
The Mammoth Book of Really Silly Jokes:
Humour for the whole family
By Geoff Tibballs
London: Constable & Robinson, Ltd
2011
Pg. ?:
Why did the banana go to the doctor?
Because it wasn’t peeling well.
 
Google Books
The Super, Epic, Mega Joke Book for Kids
By Whee Winn
Grand Rapids, MI: Zonderkidz
2016
Pg. ?:
Why did the banana go to the doctor?
It wasn’t peeling very well.