Complex sentence: Since its creation in 1990, it has maintained a professed focus on an independent college preparatory curriculum, though in April 2007, it received authorization from the International Baccalaureate Organization to include the IB Diploma Program in its curriculum.
Split into simpler sentences: Since its creation in 1990, it has maintained a focus on an independent college preparatory curriculum. In April 2007, it received authorization from the International Baccalaureate Organization to include the IB Diploma Program in its curriculum.