He usually publishes the result of his studies on the Quarterly Journal of Applied Mathematics and Mechanics (http://www3.oup.co.uk/qjmamj/)
... 18, 8.0% from 18 to 24, 31.0% from 25 to 44, 21.9% from 45 to 64, and 16.9% who are 65 years of age or older. The median age is 39 years. For every 100 females there are ...