Simplify the following text for a Grade 9 native English-speaking person.
Original: When Hooper fell into financial difficulties , the Britannica was managed by Sears Roebuck for 18 years ( 1920 â `` 23 , 1928 â `` 43 ) .
Simplified: When Hooper had financial problems , the Britannica was managed by Sears Roebuck for about 18 years ( 1920 â `` 1923 , 1928 â `` 1943 ) .