user: Question: What is the rating/share for episode 13?
Columns: ['Episode #', 'US air date', 'Rating', 'Share', 'Rating/Share (18–49)', 'Viewers (millions)']
Types: ['real', 'text', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'Thursday, April 9, 2009', '6.5', '11', '2.6/8', 10.21]
SQL:

assistant: SELECT "Rating/Share (18–49)" FROM "Table" WHERE "Episode #" = 13.0;