Simplify the following text for a Grade 9 native English-speaking person.
Original: Because the -900 retains the same exit configuration of the -800 , seating capacity is limited to 177 seats in two classes , or 189 in a single-class layout .
Simplified: Because the -900 retained the same number of exits as the -800 , seating capacity was limited to 189 in a single-class layout .