Complex sentence: Carlton le Willows is larger today than it has ever been, the number of pupils at the school has grown exponentially since its foundation in 1954; from 540 students to around 1350 today in the lower school, and around 250 in the sixth form.
Split into simpler sentences: Carlton le Willows is larger today than it has ever been. The number of pupils at the school has grown exponentially since its foundation in 1954; from 540 students to around 1350 today in the lower school, and around 250 in the sixth form.