How do you say "immigration tendency" in English?

The reasons for the visa refusal letter given by the Immigration Bureau are unknown, including immigration tendency, because the Immigration Bureau stipulates that immigrants from all over the world are welcome, but mainland immigrants are not welcome-the proportion of immigrants is too high to be clearly stated, so it is generally not mentioned separately, but more than 70% of the visa refusal in the mainland is for this reason, which is the so-called immigration tendency of China people. . .