One can use simulation of random digits to find the average number of children a couple needs to have until they have a girl or until they have 3 children. Suppose a pair of digits simulates one child, with 00 to 48 standing for a girl and 49 to 99 standing for a boy. Suppose the simulation is done 7 times with the following results: Using the table, the expected number of children a couple will have is________