Vowels 8 and 12, /ʊ/ versus /ə/    1 pair      [woodward.html]

Since the schwa has to be unstressed while /ʊ/ is likely to be prominent, only a single pair was found in the dictionary:
backwoods backwards

The density figure is too small to be worth calculating.

 

John Higgins, Shaftesbury, December 2009
updated Chiang Mai, 2024