The owner of two local restaurants has decided to randomly sample customers and gather feedback from the customers regarding the restaurants' cleanliness, service, and food quality. Over the course of five nights, five customers from each restaurant are randomly asked to fill out a survey, rating the restaurant on the three categories and using a scale from 1 to 5. A rating of 1 represents a very poor customer experience, and a rating of 5 represents an excellent customer experience. After five nights, the restaurant owner organizes and records the data, making a table for each restaurant. Calculate the mean absolute deviation of the Restaurant B's service ratings. [Note: Type your answer as a number. Do not round.]
MAD = _