Maple syrup was first collected and used by the indigenous peoples of North America. The practice was adopted by European settlers, who gradually refined production methods. Technological improvements in the 1970s further refined syrup processing. The Canadian province of Quebec is by far the largest producer, responsible for about three-quarters of the world´s output; Canadian exports of maple syrup exceed C$145 million (approximately US$130.5 million) per year. Vermont is the largest producer in the United States, generating about 5.5 percent of the global supply.