All Vietnamese refugees should be moved off the Thai border with Cambodia, and Cambodian refugees located into more stable and secure areas.

CENTERFORSECURITYPOLICY: Center for Security Policy | A New US Policy Toward Cambodia: A Commitment To A Democratic Process

So, with that, Cambodian, Loa, Hmong, Vietnamese - they're largely immigrated to the U.S. via political or refugees because of war and, in that case, their circumstances are different that would affect their educational attainment and their income levels.

NPR: Asian-Americans: Smart, High-Incomes And ... Poor?