hiː kəntˈɪnjuːd tə dˈuː ðɪs ʌntˈɪl hɪz ɹᵻtˈaɪɚmənt, wˌɪtʃ vˈɛɹiɪŋ sˈoːɹsᵻz hæv plˈeɪst bᵻtwˌiːn nˈaɪntiːnhˈʌndɹɪd sˈɛvənti tˈuː ænd nˈaɪntiːnhˈʌndɹɪd sˈɛvənti fˈoːɹ.
He continued to do this until his retirement, which varying sources have placed between 1972 and 1974.