He usually publishes the result of his studies on the Quarterly Journal of Applied Mathematics and Mechanics (http://www3.oup.co.uk/qjmamj/)
... under the age of 18, 6.7% from 18 to 24, 28.0% from 25 to 44, 25.8% from 45 to 64, and 17.2% who are 65 years of age or older. The median age is 41 years. For every ...