Complex sentence: These regular changes are of less interest to those who study employment data than the variations that occur due to the underlying state of the economy; their focus is on how unemployment in the workforce has changed, despite the impact of the regular seasonal variations.
Split into simpler sentences: These regular changes are of less interest to those who study employment data than the variations that occur due to the underlying state of the economy. Where their focus is on how unemployment in the workforce has changed, despite the impact of the regular seasonal variations.