Complex sentence: Quinnipiac moved to the Division I Northeast Conference (NEC) to again return the membership to ten, until the last major expansion took place prior to 2000 when five new schools joined the fold.
Split into simpler sentences: Quinnipiac moved to the Division I Northeast Conference (NEC) to again return the membership to ten. The last major expansion took place prior to 2000, when five new schools joined the fold.