mˈoʊst ɹˈɛfɹənsᵻz sˈaɪt ɐbˌaʊt tˈɛn pɚsˈɛnt ʌv mˈɛsɪdʒᵻz pˈɑːɹʃəli ɔːɹ sˈʌmtaɪmz kəmplˈiːtli dᵻkɹˈɪptᵻd pɹˈaɪɚ tə wˈʌn dᵻsˈɛmbɚ nˈaɪntiːnhˈʌndɹɪd fˈoːɹɾi wˈʌn, æt wˌɪtʃ tˈaɪm ɐ nˈuː ᵻdˈɪʃən ʌvðə sˈɪstəm wɛnt ˌɪntʊ ɪfˈɛkt ænd sˈɛnt ˈɔːl ðə kɹɪptˈænɐlˌɪsts bˈæk tə ðə bɪɡˈɪnɪŋ.
Most references cite about 10% of messages partially (or sometimes completely) decrypted prior to 1 December 1941, at which time a new edition of the system went into effect and sent all the cryptanalysts back to the beginning.