Researched and devised by Oliphant Jackson[?], MRCVS, the Jackson Ratio is a method of determining whether a tortoise, or a member of another chelonia species, is maintaining its optimum bodyweight, which is necessary for a successful hibernation
... 44, 26.3% from 45 to 64, and 30.2% who are 65 years of age or older. The median age is 49 years. For every 100 females there are 96.9 males. For every 100 females age ...