Input (grade 12): When Hooper fell into financial difficulties, the Britannica was managed by Sears Roebuck for roughly 18 years (1920 - 1923, 1928 - 1943).
Output (grade 10): When Hooper had financial problems, the Britannica was managed by Sears Roebuck for about 18 years (1920 - 1923, 1928 - 1943).