The main reasons are:

First, at present, most local normal universities offer geographical science (normal class) majors, with many students, and most of them think that there is a great possibility of afterlife, so they choose normal universities;

Second, geography postgraduates in Central China Normal University don't take advanced mathematics, but Southwest University takes it. Many students don't like studying mathematics, so they choose Huazhong Normal University.

Third, Huazhong Normal University is relatively closer to the east, and Southwest University is in the west. Not many people are willing to go.

However, this is only relative. As more and more students apply for graduate students, many schools have low admission rates and high scores.