Which year was to be consecrated as the Jubilee, when liberty was proclaimed in the land?

Answer: The fiftieth year

The fiftieth year was the Jubilee: liberty was proclaimed and each person returned to his property and clan.

“So you are to consecrate the fiftieth year and proclaim liberty in the land for all its inhabitants. It shall be your Jubilee, when each of you is to return to his property and to his clan. The fiftieth year will be a Jubilee for you; you are not to sow the land or reap its aftergrowth or harvest the untended vines.”— Leviticus 25:10-11 (BSB)