Complex sentence: The government tried to control production by registering designated families as hereditary saltern households who could not change their occupation or where they lived but were required to produce a yearly quota of salt (in the early years a little more than 3,000 catties).
Split into simpler sentences: The government tried to control production by registering designated families as hereditary salt producing households. These families could not change their occupation or where they lived but were required to produce a yearly quota of salt (in the beginning, a little more than 3,000 catties).