What are two reasons the trend in immigration changed?

Migration and Refugees. Migration issues are fraught with moral positions, confusion, and unexpected connections. Pulitzer Center grantees look at the effects of climate and business on migration, the efforts of immigrants to preserve their own cultural identity, and the sacrifices they make in leaving family behind

Explanation:

.In 1970, recently arrived immigrants (30%) were more likely than U.S.-born adults (23%) to have completed at least some college. However, U.S.-born adults surpassed newly arrived immigrants by 1990. In 2013, 57% of newly arrived immigrants had completed at least some college, compared with 61% of U.S. adults.

the qing dynasty placed strict limits on foreign merchants' ability to trade in china.

answer: you could try asking a family member maybe?