Complex sentence: Some of the community groups are over 40 years old-the Darlington Residents and Ratepayers Association havng evolved from the earlier Darlington Progress Association for instance, the Darlington Arts Festival as well.
Split into simpler sentences: Some of the community groups are over 40 years old. For example, the Darlington Residents and Ratepayers Association evolved from the earlier Darlington Progress Association, the Darlington Arts Festival as well.