CREATE TABLE table_name_91 (viewers INTEGER, share VARCHAR(255), rating VARCHAR(255), airdate VARCHAR(255))
Of all shows who have a rating larger than 7.8, aired on October 26, 2006, and has a share of over 14, what is the sum of the viewers?
    
SQL: SELECT SUM(viewers) FROM table_name_91 WHERE rating > 7.8 AND airdate = "october 26, 2006" AND share > 14