 In the concurrent elections, the PRI came within 11 seats of losing the majority of Chamber of Deputies, and opposition parties captured 4 of the 64 Senate seats—the first time that the PRI had failed to hold every seat in the Senate.Capitalizing on the popularity of President Salinas, however, the PRI rebounded in the mid-term congressional elections of 1991, winning 320 seats.Subsequent changes included the creation of the Federal Electoral Institute in the 1990s and the inclusion of proportional representation and first minority seats in the Senate.