Complex sentence: During the 1990s, TMISD opened its attendance boundaries to all students in the region with acceptance contingent on an application process taking into account the applicant's educational performance and behavioral record at their current school.
Split into simpler sentences: During the 1990s, TMISD opened its attendance boundaries to all students in the region. Acceptance was contingent on an application process that would take into account the applying student's current educational performance and behavioral record at their current school.