This interactive map would be a great resource if it were accurate. According to the August 2015 SEVIS by the Numbers update, there were 24,288 Vietnamese students in the US at all levels, i.e., secondary and postsecondary, but mainly the latter. I seriously doubt that the number plummeted to 11,378 active students in one month.
I also question the numbers in various states. For example, according to the interactive map there are 4,412 Vietnamese students in Florida, 1,120 in Texas, 610 in California and 69 (!) in Washington. There are individual institutions in WA that have 100-200 Vietnamese students. Texas hosted nearly 4,000 Vietnamese students last year, 21% of the national total.
I also question the “Additional Information on Students from Vietnam”, especially the education level breakdown.
I look forward to seeing the corrections but won’t hold my breath. Moral of the story: don’t believe everything you read and click on. Trust, but verify!