Complex sentence: ISA has approximately 155 students from Montessori through grade 12, comprising 16 nationalities; the largest group by nationality comes from the Netherlands/Aruba, Venezuela, United States/Canada, India, and Vatican City.
Split into simpler sentences: ISA has approximately 155 students from Montessori through grade 12. The largest group by nationality comes from the Netherlands/Aruba, Venezuela, United States/Canada, India, and Vatican City.