Please answer a question about the following article about Southampton:

The annual Southampton Boat Show is held in September each year, with over 600 exhibitors present. It runs for just over a week at Mayflower Park on the city's waterfront, where it has been held since 1968. The Boat Show itself is the climax of Sea City, which runs from April to September each year to celebrate Southampton's links with the sea.

Attendees of the Boat Show can expect to see at least how many exhibitors?
600