Longevity in 18th century England

The NYT carried a book review by Andrea Wulf, of "Behind Closed Doors" by Amanda Vickery.

Amanda Vickery, a reader in history at Royal Holloway, University of London, finds them in fashionably decorated Yorkshire mansions and dirty London lodgings, in downstairs kitchens and gilded parlors and gloomy garret rooms. She opens resolutely shut doors and peeps into the private lives of servants, aristocrats and the “polite and middling sorts” — merchants, clergy members, doctors and lawyers. “Behind Closed Doors” examines what privacy meant in 18th-century Britain and how people negotiated both their domestic space and their domestic relationships.

My purpose here is to highlight one interesting thing the reviewer says (emphasis added).

“Behind Closed Doors” also leads the reader into the rooms of spinsters and widows, an important inclusion, since in 1700 the average marriage lasted only 10 years.

Marriage ended with death (not divorce). The very different life expectancy back then should not be forgotten when thinking of history. Imagine, say you're married at twenty (probably considered a late marriage?) and it can be said that you or your spouse will, on the average, have expired by 30.