Wikipedia entity: Great Lakes
Topics: geography; lakes; forest cover
Original sentence: In the early 21st century, Lake Superior's shores are 91% forested, Lake Huron 68%, Lake Ontario 49%, Lake Michigan 41%, and Lake Erie, where logging and urbanization has been most extensive, 21%.
Quantified sentence: In the early 21st century, Lake Superior's shores are 91% forested, Lake Huron is generally forested, Lake Ontario 49%, Lake Michigan 41%, and Lake Erie, where logging and urbanization has been most extensive, 21%. 
Quantifier: generally
Percentage: 68%
Specificity: unable