premise: Earl of Burlington is a title that has been created twice, the first time in the Peerage of England in 1664 and the second in the Peerage of the United Kingdom in 1831. Since 1858, Earl of Burlington has been a courtesy title used by the Dukes of Devonshire, traditionally borne by the duke's grandson, who is the eldest son of the duke's eldest son, the Marquess of Hartington.
hypothesis: Earl of Burlington is a title over 100 years old
reason: The paragraph says the title was created in 1664, which is more than 100 years old. I think the system has a hard time with dates