Xi (Ξ ξ) is the 14th letter of the Greek alphabet and has a numeric value of 60.
... age of 18, 5.0% from 18 to 24, 29.0% from 25 to 44, 24.2% from 45 to 64, and 12.7% who are 65 years of age or older. The median age is 39 years. For every 100 females ...