Complex sentence: The school has a diverse population of approximately 1100 students; about 40% primarily speak a language other than English and 15% of the school population has been living in Canada for less than 5 years.
Split into simpler sentences: The school has about 1100 students, about 40% primarily speak a language other than English. About 15% of the school population has been living in Canada for less than 5 years.