According to Wikipedia, 1.5% of Indian immigrants to the USA are Dalit. 90% are the high castes. That is interesting coincidence to your quoted statistic of 90% thinking this is a minor problem or no problem at all.
I think you're talking about this one:
https://en.wikipedia.org/wiki/Caste_discrimination_in_the_Un...
In addition to surname, these are all questions that can be used to gather details about someone’s caste.
Or so I’m told.
Buts it’s funny when we start to care about a tiny portion of the poor people.