Main spellings (~95%)
⟨ure⟩ ~40%
After most consonants, ⟨ure⟩ includes a /j/ glide: /jʊr/.
After /l/, /ʃ/, /ʧ/, and /ʤ/, the /j/ drops and it's just /ʊr/.
⟨ur⟩ ~25%
When ⟨ur⟩ is followed by another vowel, it can produce /ʊr/.
⟨our⟩ ~20%
Found in French-derived words.
⟨oor⟩ ~10%
Only a handful of words use this spelling.