CREATE TABLE table_78362 ("Year" FLOAT, "Network" TEXT, "Lap-by-lap" TEXT, "s Color commentator" TEXT, "Pre-Race Host" TEXT, "Pre-Race Analyst ( s ) " TEXT, "Ratings" TEXT, "Viewers" TEXT)

Which Network has 17.5 million Viewers?
SELECT "Network" FROM table_78362 WHERE "Viewers" = '17.5 million'
SELECT "Network" FROM "table_78362" WHERE "Viewers" = '17.5 million'