ACT score percentiles are highly dependent on the specific population being considered. You'll find more accurate data if you look at:
* State-level ACT reports: Many states publish data on average ACT scores and percentiles for their students. Look at the official websites of the education departments in the Southwestern states you're interested in.
* Individual school reports: High schools often publish data on their students' average ACT scores and percentiles.
* Colleges' admissions data: Colleges in the Southwest may publish the ACT scores of their admitted students, offering a glimpse into the range of scores from those who apply.
Without a more specific geographic region, providing 25th-75th percentile ACT composite scores for "Southwestern" is unreliable and potentially misleading.