 How many million viewers did episode number 63 have?
CREATE TABLE table_2737 (
    "No." real,
    "#" real,
    "Title" text,
    "Directed by" text,
    "Written by" text,
    "U.S. viewers (million)" text,
    "Rank (week)" real,
    "Original air date" text
)
SELECT "U.S. viewers (million)" FROM table_2737 WHERE "No." = '63'