Seattle times published data of percentage of unvaccinated children in Seattle schools (https://www.seattletimes.com/seattle-news/data/are-measles-a...).
Each and every school in top 10 is a private school. In Seattle, private schools cost an average of $25k/year. I bet illegal immigrants are not sending their children to the private schools that cost $25k every year when public schools are free.
The top schools is Waldorf which costs $20k/year for grade 1-8 and $25k for 9-12. This fee is only for 9 months of school. This school has 22% unvaccinated children. I bet there are exactly 0 children in this school from illegal immigrant families.