Complex sentence: The graduating class of 2006 had 145 students, and enrollment continues to decrease, which has led to the sharing of services with Dunkirk, New York and Brocton, New York.
Split into simpler sentences: The graduating class of 2006 had 145 students, and enrollment continues to decrease. It's because of this that the sharing of services with Dunkirk, New York and Brocton, New York.