Final answer:
Newfoundland and Labrador experienced the most significant population decline from 1996 to 2016 due mainly to economic difficulties in the fishing industry, challenging living conditions, and its relative isolation.
Step-by-step explanation:
The Canadian province that suffered the largest population decline between 1996 and 2016 is Newfoundland and Labrador. The province has faced economic challenges due to the decline in the fishing economy, particularly because of overfishing in the North Atlantic.
As a result, many working-age individuals and families have moved out of the province to seek employment elsewhere, leading to a significant decline in population. This population decrease is compounded by the province's poor soil quality and harsh climate, which makes agriculture difficult and does little to attract new residents. Additionally, Newfoundland and Labrador is somewhat isolated, being removed from the major population centers of Canada and the eastern United States, which further challenges its economic development and population retention.