He usually publishes the result of his studies on the Quarterly Journal of Applied Mathematics and Mechanics (http://www3.oup.co.uk/qjmamj/)
... 12.7% who are 65 years of age or older. The median age is 39 years. For every 100 females there are 104.2 males. For every 100 females age 18 and over, there are 97.8 ...