Amphibracs are never used to construct a whole, serious poem. So they mainly occur as variants within, say, an anapaestic structure.
... size is 2.57 and the average family size is 3.08. In the town the population is spread out with 22.3% under the age of 18, 6.3% from 18 to 24, 31.0% from 25 to 44, ...