Read this: Numerous plays are put on every year at Eton College; there is one main theatre, called the Farrer (seating 400) and 2 Studio theatres, called the Caccia Studio and Empty Space (seating 90 and 80 respectively). There are about 8 or 9 house productions each year, around 3 or 4 "independent" plays (not confined solely to one house, produced, directed and funded by Etonians) and three school plays, one specifically for boys in the first two years, and two open to all years. The School Plays have such good reputations that they are normally fully booked every night. Productions also take place in varying locations around the School, varying from the sports fields to more historic buildings such as Upper School and College Chapel.

How many plays are held in Empty Space each year?
What is the answer? (If it cannot be answered, return "unanswerable")
unanswerable